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  • 351. Xia, Yang
    et al.
    Stilbs, Peter
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    The First Study of Cartilage by Magnetic Resonance: A Historical Account2016In: Cartilage, ISSN 1947-6035, E-ISSN 1947-6043, Vol. 7, no 4, p. 293-297Article in journal (Refereed)
    Abstract [en]

    Objective. To recap the historical journey leading to the first cartilage research article using nuclear magnetic resonance (NMR), published in 1955 by 2 Swedish researchers, Erik Odeblad and Gunnar Lindstrom. Design. Extensive Internet search utilizing both English and Swedish websites, and reading the dissertations available at the Royal Institute of Technology (Stockholm, Sweden) and via interlibrary loans at Oakland University (Michigan, USA). Results. Using a primitive NMR instrument that Lindstrom built for his graduate research at the Nobel Institute for Physics (Stockholm, Sweden), Odeblad and Lindstrom studied the characteristics of the NMR signal in calf cartilage. The authors wrote, "In cartilage and fibrous tissue, in which the proton signals probably arise from highly viscous water with short spin-lattice relaxation time, the signals were also larger than would correspond to the water content." The authors speculated the signal differences between water and biological tissues could be attributed to the absorption and organization of the water molecules to the proteins in the tissue, which was remarkably accurate. Conclusions. It is quite certain that Odeblad and Lindstrom published the first biomedical study using NMR in 1955. In this article, cartilage and a number of other biological tissues were examined for the first time using NMR.

  • 352.
    Xu, Bo
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Bi, Dongqin
    Hua, Yong
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Liu, Peng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Cheng, Ming
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Graetzel, Michael
    Kloo, Lars
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Hagfeldt, Anders
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD. Dalian University of Technology (DUT), China.
    A low-cost spiro[fluorene-9,9 '-xanthene]-based hole transport material for highly efficient solid-state dye-sensitized solar cells and perovskite solar cells2016In: Energy & Environmental Science, ISSN 1754-5692, E-ISSN 1754-5706, Vol. 9, no 3, p. 873-877Article in journal (Refereed)
    Abstract [en]

    A low-cost spiro[fluorene-9,9'-xanthene] (SFX) based organic hole transport material (HTM) termed X60 was designed and synthesized using a two-step synthetic route. Devices with X60 as HTM showed high power conversion efficiencies (PCEs) amounting to 7.30% in solid-state dye-sensitized solar cells (ssDSCs) and 19.84% in perovskite solar cells (PSCs), under 100 mW cm(-2) AM1.5G solar illumination. To the best of our knowledge, this is the first example of an easily synthesized spiro-structured HTM that shows comparable performance with respect to the well-known HTM Spiro-OMeTAD in both ssDSCs and PSCs. Furthermore, the facile synthesis of X60 from commercially available starting materials makes this HTM very promising for large-scale industrial production in the future.

  • 353.
    Xu, Bo
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Gabrielsson, Erik
    Safdari, Majid
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Cheng, Ming
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Hua, Yong
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Tian, Haining
    Gardner, James M.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Kloo, Lars
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    1,1,2,2-Tetrachloroethane (TeCA) as a Solvent Additive for Organic Hole Transport Materials and Its Application in Highly Efficient Solid-State Dye-Sensitized Solar Cells2015In: Advanced Energy Materials, ISSN 1614-6832, Vol. 5, no 10, article id 1402340Article in journal (Refereed)
    Abstract [en]

    A low-cost, chlorinated hydrocarbon solvent, 1,1,2,2-tetrachloroethane (TeCA), is used as an effective additive for the triarylamine-based organic hole-transport material, Spiro-OMeTAD, which is successfully applied in highly efficient solid-state dye-sensitized solar cells. A record power conversion efficiency of 7.7% is obtained by using the donor (D)-π-acceptor (A)-dye, LEG4, in combination with the new method of TeCA-doping of the hole-transporting material Spiro-OMeTAD.

  • 354.
    Xu, Bo
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Huang, Jing
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Ågren, Hans
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Kloo, Lars
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Hagfeldt, Anders
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    AgTFSI as p-Type Dopant for Efficient and Stable Solid-State Dye-Sensitized and Perovskite Solar Cells2014In: ChemSusChem, ISSN 1864-5631, E-ISSN 1864-564X, Vol. 7, no 12, p. 3252-3256Article in journal (Refereed)
    Abstract [en]

    A silver-based organic salt, silver bis(trifluoromethane-sulfonyl) imide (AgTFSI), was employed as an effective p-type dopant for the triarylamine-based organic hole-transport material Spiro-MeOTAD, which has been successfully applied in solid-state dye-sensitized solar cells (ssDSCs) and perovskite solar cells (PSCs). The power conversion efficiencies (PCEs) of AgTFSI-doped devices improved by 20%, as compared to the device based on the commonly used oxygen doping both for ssDSCs and PSCs. Moreover, the solid-state dye-sensitized devices exposed to AgTFSI as dopant showed considerably better stability than those of oxygen doped, qualifying this p-type dopant as a promising alterative for the preparation of highly efficient as well as stable ssDSCs and PSCs for the future.

  • 355.
    Xu, Bo
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Sheibani, Esmaeil
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Liu, Peng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Zhang, Jinbao
    Tian, Haining
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD. Uppsala University, Sweden.
    Vlachopoulos, Nick
    Boschloo, Gerrit
    Kloo, Lars
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Hagfeldt, Anders
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD. Dalian University of Technology (DUT)Dalian, China .
    Carbazole-Based Hole-Transport Materials for Efficient Solid-State Dye-Sensitized Solar Cells and Perovskite Solar Cells2014In: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 26, no 38, p. 6629-6634Article in journal (Refereed)
    Abstract [en]

    (Graph Presented) Two carbazole-based small molecule hole-transport materials (HTMs) are synthesized and investigated in solid-state dye-sensitized solar cells (ssDSCs) and perovskite solar cells (PSCs). The HTM X51-based devices exhibit high power conversion efficiencies (PCEs) of 6.0% and 9.8% in ssDSCs and PSCs, respectively. These results are superior or comparable to those of 5.5% and 10.2%, respectively, obtained for the analogous cells using the state-of-the-art HTM Spiro-OMeTAD.

  • 356.
    Xu, Bo
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD. University of Washington, United States.
    Zhang, J.
    Hua, Yong
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Liu, Peng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Wang, Linqin
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Ruan, C.
    Li, Yuanyuan
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Boschloo, G.
    Johansson, E. M. J.
    Kloo, Lars
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Hagfeldt, A.
    Jen, A. K. -Y
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Tailor-Making Low-Cost Spiro[fluorene-9,9′-xanthene]-Based 3D Oligomers for Perovskite Solar Cells2017In: Chem, ISSN 2451-9308, Vol. 2, no 5, p. 676-687Article in journal (Refereed)
    Abstract [en]

    The power-conversion efficiencies (PCEs) of perovskite solar cells (PSCs) have increased rapidly from about 4% to 22% during the past few years. One of the major challenges for further improvement of the efficiency of PSCs is the lack of sufficiently good hole transport materials (HTMs) to efficiently scavenge the photogenerated holes and aid the transport of the holes to the counter-electrode in the PSCs. In this study, we tailor-made two low-cost spiro[fluorene-9,9′-xanthene] (SFX)-based 3D oligomers, termed X54 and X55, by using a one-pot synthesis approach for PSCs. One of the HTMs, X55, gives a much deeper HOMO level and a higher hole mobility and conductivity than the state-of-the-art HTM, Spiro-OMeTAD. PSC devices based on X55 as the HTM show a very impressive PCE of 20.8% under 100 mW·cm−2 AM1.5G solar illumination, which is much higher than the PCE of the reference devices based on Spiro-OMeTAD (18.8%) and X54 (13.6%) under the same conditions.

  • 357. Yang, Lei
    et al.
    Zhang, Jinbao
    Shen, Yang
    Park, Byung-Wook
    Bi, Dongqin
    Häggman, Leif
    Johansson, Erik M. J.
    Boschloo, Gerrit
    Hagfeldt, Anders
    Vlachopoulos, Nick
    Snedden, Alan
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Kloo, Lars
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Jarboui, Adel
    Chams, Amani
    Perruchot, Christian
    Jouini, Mohamed
    New Approach for Preparation of Efficient Solid-State Dye-Sensitized Solar Cells by Photoelectrochemical Polymerization in Aqueous Micellar Solution2013In: Journal of Physical Chemistry Letters, ISSN 1948-7185, E-ISSN 1948-7185, Vol. 4, no 23, p. 4026-4031Article in journal (Refereed)
    Abstract [en]

    Hereby, we present a new, cost-effective, and environmentally friendly method of preparing an efficient solid-state dye-sensitized solar cell (sDSC) using a PEDOT conducting polymer as the hole conductor and a recently developed organic sensitizer. PEDOT is generated and deposited on the dye-sensitized TiO2 electrode by in situ photoelectropolymerization of bis-EDOT in aqueous micellar solution. The advantages of this approach are the use of water as the solvent and the obtainment of a sDSC simply by adding a silver layer on the as-obtained polymer film deposited on dye/TiO2 without the need for electrolytic solution. The sDSC containing the film prepared as above is compared to those where the organic dye is used to generate the same polymer film but in organic solvent. The energy conversion efficiency values of the two cells appear comparable, 4.8% for sDSC prepared in the aqueous-phase polymerized PEDOT and 6% for the sDSC prepared with in organic-phase polymerized PEDOT.

  • 358.
    Yang, Miao
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Radiation Induced Processes at Solid-Liquid Interfaces2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In the thesis, the reactions between water radiolysis products—H2O2, HO• and O2—with metals and metal oxides utilized in nuclear industry are studied. The reactions include not only surface reactions, e.g. redox reactions and catalytic decomposition of H2O2, but also solution reactions (Haber-Weiss reactions). To study the interfacial reactions, it is crucial to monitor the dissolution of the solid material, reactivity of H2O2 and formation of the intermediate hydroxyl radicals.Hydroxyl radicals are captured by probe (Tris or methanol) to generate CH2O which can be quantified by the modified Hantzsch method. The results from γ-irradiation experiments on homogeneous system show that the conversion yield of CH2O from hydroxyl radicals is affected by O2 and pH. A mechanism of CH2O production from Tris is proposed.Besides, the consumption rate of H2O2 in the H2O2/ZrO2/Tris system is found to be influenced by Tris. A mechanism for the catalytic decomposition of H2O2 upon ZrO2 surface is proposed which includes independent surface adsorption sites for H2O2 and Tris. Moreover, it is demonstrated that the deviation of detected CH2O concentration by the modified Hantzsch method from actual concentration increases with increasing [H2O2]0/[CH2O]0.The inhibition of sulfide on the radiation induced dissolution of UO2 is confirmed and is dependent on sulfide concentration. And the inhibition of sulfide is independent to that of H2/Pd.It is found that the reactivity of H2O2 and dynamics of CH2O formation are different for the studied materials in the H2O2/MxOy/Probe system. The kinetic parameters, such as rate constant, activation energy, frequency factors are determined.Both surface and solution reactions are observed in the aqueous W(s)/H2O2/Tris system. It is also demonstrated that Haber-Weiss reactions which produce HO• continuously are dominating. Furthermore, it is found that hydroxyl radicals are formed simultaneously during the dissolution of W in aerobic aqueous system.The knowledge conveyed by the thesis is relevant to nuclear technological applications, as well as the applications related in photocatalysis, biochemistry, corrosion science, catalysis and optics/electronics.

  • 359.
    Yang, Miao
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Barreiro Fidalgo, Alexandre
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Sundin, Sara
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Jonsson, Mats
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Inhibition of radiation induced dissolution of UO2 by sulfide-A comparison with the hydrogen effect2013In: Journal of Nuclear Materials, ISSN 0022-3115, E-ISSN 1873-4820, Vol. 434, no 1-3, p. 38-42Article in journal (Refereed)
    Abstract [en]

    In this work we have studied the influence of H2S on radiation induced dissolution of spent nuclear fuel using simple model systems. The reaction between H2O2 and H2S/HS- has been studied experimentally as well as the effect of H2S/HS - on γ-radiation induced dissolution of a UO2 pellet. The experiments clearly show that the reaction of H2O 2 and H2S/HS- is fairly rapid and that H 2O2 and H2S/HS- stoichiometry is favorable for inhibition. Radiolysis experiments show that H2S/ HS- can effectively protect UO2 from oxidative dissolution. The effect depends on sulfide concentration in combination with dose rate. Autoclave experiments were also conducted to study the role of H 2S/HS- in the reduction of U(VI) in the presence and absence of H2 and Pd particles in anoxic aqueous solution. The aqueous solutions were pressurized with H2 or N2 and two different concentrations of H2S/HS- were used in the presence and absence of Pd. No catalytic effect of Pd on the U(VI) reduction by H2S/HS- could be found in N2 atmosphere. U(VI) reduction was found to be proportional to H2S/HS- concentration in H2 and N2 atmosphere. It is clearly shown the Pd catalyzed H2 effect is more powerful than the effect of H2S/HS-. H2S/HS- poisoning of the Pd catalyst is not observed under the present conditions.

  • 360.
    Yang, Miao
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Jonsson, Mats
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Evaluation of the O-2 and pH Effects on Probes for Surface Bound Hydroxyl Radicals2014In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 118, no 15, p. 7971-7979Article in journal (Refereed)
    Abstract [en]

    Interfacial reactions between H2O2 and metal oxides are important in several fields but are yet not fully understood. Recently, tris(hydroxymethyl)aminomethane (Tris) was used as a probe in detecting the intermediate hydroxyl radical (HO center dot) during such process via the formation of formaldehyde (CH2O). In this work, we evaluate two probes (methanol and Tris) for detection of surface bound HO center dot by investigating the O-2 and pH effects on the production of formaldehyde. Moreover, we also examine the pH effect on the production of formaldehyde from Tris in the catalytic decomposition of H2O2 on ZrO2. The influence of O-2 and pH on the yield of formaldehyde under homogeneous conditions was studied via gamma-radiolysis of water. The solution was either deoxygenated or saturated with gas containing 20% 02, and the pH was ranging from 7.0 to 9.0. In the gamma-radiolysis experiment, O-2 shows a strong impact on the yield of formaldehyde: 14-68% for methanol and 16-29% for Tris. However, during the catalytic decomposition of H2O2, O-2 only enables a 30% enhancement of the production of CH2O when using Tris as the scavenger. While for methanol, the O-2 effect is almost negligible, and the production of CH2O from Tris is much higher than that from methanol. For practical reasons, only Tris was studied when evaluating the pH effect. A significant increase in the production of formaldehyde is observed by increasing pH during gamma-radiolysis of water while an even more pronounced pH-dependent increase is observed in the catalytic decomposition of H2O2 on ZrO2. The former indicates that the scavenging yield is base-catalyzed while the latter indicates that the formation of HO center dot is also base-catalyzed. On the basis of the observed effects of O-2 and pH, we propose a mechanism for the production of formaldehyde from Tris. The mechanism accounts for the observed impacts of O-2 and pH on the yield of formaldehyde.

  • 361.
    Yang, Miao
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Jonsson, Mats
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Surface reactivity of hydroxyl radicals formed upon catalytic decomposition of H2O2 on ZrO22015In: Journal of Molecular Catalysis A: Chemical, ISSN 1381-1169, E-ISSN 1873-314X, Vol. 400, p. 49-55Article in journal (Refereed)
    Abstract [en]

    In this work, the surface reactivity of hydroxyl radicals formed upon catalytic decomposition of H2O2 on ZrO2 in the presence of Tris(hydroxymethyl) aminomethane was studied experimentally. Two sets of competition experiments were performed: the competition between H2O2 and Tris for the surface bound hydroxyl radical (HO) and between O2 and H2O2 for the hydroxymethyl radical (CH2OH) (precursor for formaldehyde). A 5-fold increase in initial concentration of Tris or H2O2 does not lead to a 5-fold increase in CH2O formation (only by a factor of 2-3 in the studied concentration range). The O2-dependent enhancement of the final production of CH2O becomes weaker upon increasing the initial concentration of H2O2 from 0.5 mM to 5 mM. The final production of CH2O becomes independent of the concentration of Tris when [Tris]0 is above 100 mM, i.e., the surface is saturated with Tris at this concentration. Based on the experimental results, a site-specific mechanism of H2O2 decomposition on the surface of ZrO2 was proposed. This model was used for numerical simulations of the dynamics of the reaction system. The kinetics was simulated using the kinetic simulation software Gepasi 3.0 and the results are in good agreement with the experimental observations.

  • 362.
    Yang, Miao
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry. Wuhan University of Technology, China.
    Soroka, Inna
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Jonsson, Mats
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Exploring the limitations of the Hantzsch method used for quantification of hydroxyl radicals in systems of relevance for interfacial radiation chemistry2017In: Radiation Physics and Chemistry, ISSN 0969-806X, E-ISSN 1879-0895, Vol. 130, p. 1-4Article in journal (Refereed)
    Abstract [en]

    In the presence of Tris or methanol, hydroxyl radicals in systems of relevance for interfacial radiation chemistry can be quantified indirectly via the Hantzsch method by determining the amount of the scavenging product formaldehyde formed. In this work, the influence of the presence of H2O2 on the Hantzsch method using acetoacetanilide (AAA) as derivatization reagent is studied. The experiments show that the measured CH2O concentration deviates from the actual concentration in the presence of H2O2 and the deviation increases with increasing [H2O2]0/[CH2O]0. The deviation is negative, i.e., the measured formaldehyde concentration is lower than the actual concentration. This leads to an underestimation of the hydroxyl radical production in systems containing significant amount of H2O2. The main reason for the deviation is found to be three coupled equilibria involving H2O2, CH2O and the derivative produced in the Hantzsch method.

  • 363.
    Yang, Miao
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Soroka, Inna
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Jonsson, Mats
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Hydroxyl Radical Production in Aerobic Aqueous Solution containing Metallic TungstenManuscript (preprint) (Other academic)
  • 364.
    Yang, Miao
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Soroka, Inna
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Jonsson, Mats
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Hydroxyl radical production in aerobic aqueous solution containing metallic tungsten2015In: Catalysis communications, ISSN 1566-7367, E-ISSN 1873-3905, Vol. 71, p. 93-96Article in journal (Refereed)
    Abstract [en]

    Abstract In this work, we investigate the production of hydroxyl radicals from the W(s)/air aqueous system by quantifying the amount of scavenging product formaldehyde via the modified Hantzsch method. Tris(hydroxymethyl) aminomethane (Tris) and methanol are used as probe for HO. Meanwhile, the amount of dissolved tungsten is determined by ICP-OES. A turnover point ([W] ≈ 200 μM) is observed in the Tris case after which the production rate of CH2O overwhelms the constant rate in the methanol case. Based on the results, a mechanism is proposed for the studied system including both surface and solution reactions.

  • 365.
    Yang, Miao
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Soroka, Inna
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Jonsson, Mats
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Influence of H2O2 on the Quantitative Determination of Formaldehyde using Acetoacetanilide as Detection Reagent in the Hantzsch MethodManuscript (preprint) (Other academic)
  • 366.
    Yang, Miao
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Zhang, Xian
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Grosjean, Alex
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Soroka, Inna
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Jonsson, Mats
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Kinetics and Mechanism of Reactions between H2O2 and Tungsten PowderManuscript (preprint) (Other academic)
    Abstract [en]

    In this work, the reaction between H2O2 and tungsten powder in the presence of Tris(hydroxymethyl) aminomethane was studied experimentally. The production of hydroxyl radicals can be quantified indirectly by quantifying the scavenging product formaldehyde (CH2O). XRD, XPS and SEM analysis shows that no significant structural or compositional changes occur after reaction. We compared H2O2 consumption and CH2O formation in both heterogeneous W(s)/H2O2/Tris system and homogenous W(aq)/H2O2/Tris system. Increasing the amount of W powder leads to the increase in dissolution rate of W species, insignificant increase of H2O2 consumption rate and the decrease of final CH2O production. By contrast, the consumption rate of H2O2 increases as increasing the concentration of dissolved W species. Based on the experimental results, a mechanism of H2O2 reacting with W powder in the presence of Tris is proposed. The mechanism well explained the relationship between surface reactions and homogeneous Haber-Weiss reactions.

  • 367.
    Yang, Miao
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Zhang, Xian
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Grosjean, Alex
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Soroka, Inna
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Jonsson, Mats
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Kinetics and Mechanism of the Reaction between H2O2 and Tungsten Powder in Water2015In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 119, no 39, p. 22560-22569Article in journal (Refereed)
    Abstract [en]

    In this work, the reaction between H2O2 and tungsten powder in the presence of Tris(hydroxymethyl) aminomethane was studied experimentally. The production of hydroxyl radicals can be quantified indirectly by quantifying the scavenging product formaldehyde (CH2O). XRD, XPS, and SEM analysis shows that no significant structural or compositional changes occur after reaction. We compared H2O2 consumption and CH2O formation in both heterogeneous W(s)/H2O2/Tris system and homogeneous W(aq)/H2O2/Tris system. Increasing the amount of W powder leads to the increase in dissolution rate of W species, insignificant increase of H2O2 consumption rate and the decrease of final CH2O production. By contrast, the consumption rate of H2O2 increases as increasing the concentration of dissolved W species. Based on the experimental results, a mechanism of H2O2 reacting with W powder in the presence of Tris is proposed. The mechanism well explained the relationship between surface reactions and homogeneous Haber–Weiss peroxide chain breakdown.

  • 368. Yang, Sheng-Chun
    et al.
    Wang, Yong-Lei
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.). KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Jiao, Gui-Sheng
    Qian, Hu-Jun
    Lu, Zhong-Yuan
    Accelerating electrostatic interaction calculations with graphical processing units based on new developments of ewald method using non-uniform fast fourier transform2016In: Journal of Computational Chemistry, ISSN 0192-8651, E-ISSN 1096-987X, Vol. 37, no 3, p. 378-387Article in journal (Refereed)
    Abstract [en]

    We present new algorithms to improve the performance of ENUF method (F. Hedman, A. Laaksonen, Chem. Phys. Lett. 425, 2006, 142) which is essentially Ewald summation using Non-Uniform FFT (NFFT) technique. A NearDistance algorithm is developed to extensively reduce the neighbor list size in real-space computation. In reciprocal-space computation, a new algorithm is developed for NFFT for the evaluations of electrostatic interaction energies and forces. Both real-space and reciprocal-space computations are further accelerated by using graphical processing units (GPU) with CUDA technology. Especially, the use of CUNFFT (NFFT based on CUDA) very much reduces the reciprocal-space computation. In order to reach the best performance of this method, we propose a procedure for the selection of optimal parameters with controlled accuracies. With the choice of suitable parameters, we show that our method is a good alternative to the standard Ewald method with the same computational precision but a dramatically higher computational efficiency.

  • 369. Yu, Y.
    et al.
    Li, X.
    Shen, Z.
    Zhang, X.
    Liu, Peng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Gao, Y.
    Jiang, T.
    Hua, J.
    Restrain recombination by spraying pyrolysis TiO2 on NiO film for quinoxaline-based p-type dye-sensitized solar cells2017In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 490, p. 380-390Article in journal (Refereed)
    Abstract [en]

    In this work, we reported two new quinoxaline-based sensitizers (BQI and BQII) for p-type dye-sensitized solar cells (p-DSSCs) featuring carboxylic acid and pyridine as anchoring groups, respectively, in combination with triphenylamine donor. The optical, electrochemical and photovoltaic properties of BQI and BQII were investigated. Results showed that BQI-based p-DSSC with carboxylic acid anchoring group obtained higher photoelectric conversion efficiency (PCE) of 0.140%. To further optimize the device performance, we added a layer of TiO2 on the surface of NiO film as a barrier layer, which contributed to the improvement of the photocurrent density from 3.00 to 3.84 mA cm−2. The p-DSSCs based on BQI reached the PCE of 0.20% at an irradiance of 100 mW cm−2 simulated AM1.5 sunlight. Electrochemical impedance spectroscopy (EIS) analysis indicated that the hole recombination resistance of p-DSSCs with TiO2 barrier layer was larger than that of the naked NiO film. Meanwhile, the surface profile of TiO2 on NiO film was verified by scanning electron microscope (SEM), X-ray diffraction (XRD) and the time of flight-secondary ion mass spectrometry (TOF-SIMS).

  • 370.
    Yu, Ze
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Vlachopoulos, Nick
    Hagfeldt, Anders
    Kloo, Lars
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Incompletely solvated ionic liquid mixtures as electrolyte solvents for highly stable dye-sensitized solar cells2013In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 3, no 6, p. 1896-1901Article in journal (Refereed)
    Abstract [en]

    Ionic liquids have been intensively investigated as alternative stable electrolyte solvents for dye-sensitized solar cells (DSCs). A highest overall conversion efficiency of over 8% has been achieved using a ionic-liquid-based electrolyte in combination with an iodide/triiodide redox couple. However, the relatively high viscosities of ionic liquids require higher iodine concentration in the electrolyte due to mass-transport limitations of the triiodide ions. The higher iodine concentration significantly reduces the photovoltaic performance, which normally are lower than those using organic solvent-based electrolytes. Here, the concept of incompletely solvated ionic liquid mixtures (ISILMs) is introduced and represents a conceptually new type of electrolyte solvent for DSCs. It is found that the photovoltaic performance of ISILM-based electrolytes can rival that of organic solvent-based electrolytes. Furthermore, the vapor pressures of ISILMs are found to be considerably lower than that for pure organic solvents. Stability tests show that ISILM-based electrolytes provide highly stable DSCs under light soaking conditions. Thus, ISILM-based electrolytes offer a new platform to develop more efficient and stable DSC devices of relevance to future large-scale applications.

  • 371. Zander, Thomas
    et al.
    Wieland, D. C. Florian
    Raj, Akanksha
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Wang, Min
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Nowak, Benedikt
    Krywka, Christina
    Dédinaité, Andra
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry. SP Tech Res Inst Sweden.
    Claesson, Per Martin
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science. SP Tech Res Inst Sweden.
    Garamus, Vasil M.
    Schreyer, Andreas
    Willumeit-Romer, Regine
    The influence of hyaluronan on the structure of a DPPC-bilayer under high pressures2016In: Colloids and Surfaces B: Biointerfaces, ISSN 0927-7765, E-ISSN 1873-4367, Vol. 142, p. 230-238Article in journal (Refereed)
    Abstract [en]

    The superior lubrication properties of synovial joints have inspired many studies aiming at uncovering the molecular mechanisms which give rise to low friction and wear. However, the mechanisms are not fully understood yet, and, in particular, it has not been elucidated how the biolubricants present at the interface of cartilage respond to high pressures, which arise during high loads of joints. In this study we utilize a simple model system composed of two biomolecules that have been implied as being important for joint lubrication. It consists of a solid supported dipalmitoylphosphatidylcholin (DPPC) bilayer, which was formed via vesicles fusion on a flat Si wafer, and the anionic polysaccharide hyaluronan (HA). We first characterized the structure of the HA layer that adsorbed to the DPPC bilayers at ambient pressure and different temperatures using X-ray reflectivity (XRR) measurements. Next, XRR was utilized to evaluate the response of the system to high hydrostatic pressures, up to 2 kbar (200 MPa), at three different temperatures. By means of fluorescence microscopy images the distribution of DPPC and HA on the surface was visualized. Our data suggest that HA adsorbs to the headgroup region that is oriented towards the water side of the supported bilayer. Phase transitions of the bilayer in response to temperature and pressure changes were also observed in presence and absence of HA. Our results reveal a higher stability against high hydrostatic pressures for DPPC/HA composite layers compared to that of the DPPC bilayer in absence of HA.

  • 372. Zanonato, Pier Luigi
    et al.
    Di Bernardo, Plinio
    Fischer, Andreas
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Grenthe, Ingmar
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Chemical equilibria in the UO22+-H2O2-F-/OH(-)systems and possible solution precursors for the formation of [Na-6(OH2)(8)]@[UO2(O-2) F](24)(18-)and [Na-6(OH2)(8)]@ [UO2(O-2) OH](24)(18-)clusters2013In: Dalton Transactions, ISSN 1477-9226, E-ISSN 1477-9234, Vol. 42, no 28, p. 10129-10137Article in journal (Refereed)
    Abstract [en]

    The focus of this study is on the relationship between uranyl(VI) poly-peroxo clusters in the solid state and their possible precursors in solution. For this purpose, the complex formation in the ternary U(VI)-H2O2-F-system has been studied by potentiometric titrations, measuring p[H+] and p[F-], revealing that significant amounts of ternary uranyl(VI)-peroxide-fluoride complexes are formed. Based on the analysis of these data we find that there are two models consistent with structure data and previous speciation in the uranyl(VI)peroxide- carbonate system (Dalton. Trans., 2012, 41, 11635-11641). One model contains ternary complexes (UO2)(4)(O-2)(4)F- and (UO2)(4)(O-2)(4)F-2(2-) and the other (UO2)(4)(O-2) (F-)(4) and (UO2)(5)(O-2)(5)F-3(3-); we have chosen the second model as the one most consistent with available information. We suggest that (UO2)(4)(O-2)(4)(F-) is a building block in the U-24 cluster, [Na-6(OH2)(8)]@[UO2(O-2)F](24)(18-) identified in a single-crystal X-ray diffraction study of the solid phase that slowly precipitates from the slightly acidic test solutions. At p[H+] approximate to 9.5, a new solid phase is formed that contains the cluster [Na-6(OH2)(8)]@[UO2(O-2)OH](24)(18-), also identified from an X-ray structure. Both structures contain. 2-. 2 bridging peroxide and. 2 bridging fluoride or hydroxide ions, respectively. As fluoride bridges are unknown in solution coordination chemistry, it is unlikely that the U-24 fluoride cluster is formed in solution. We suggest that both the solid state fluoride and hydroxide clusters are formed in the crystallization from smaller precursors identified in solution. The study illustrates the importance of accurate control of the solution chemistry when preparing poly-peroxo-metallate clusters and also that the mechanism of their formation is still an open field of research.

  • 373. Zhang, F.
    et al.
    Liang, X.
    Zhang, W.
    Wang, Yong-Lei
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Wang, H.
    Mohammed, Y. H.
    Song, B.
    Zhang, R.
    Yuan, J.
    A unique iridium(III) complex-based chemosensor for multi-signal detection and multi-channel imaging of hypochlorous acid in liver injury2017In: Biosensors & bioelectronics, ISSN 0956-5663, E-ISSN 1873-4235, Vol. 87, p. 1005-1011Article in journal (Refereed)
    Abstract [en]

    Although hypochlorous acid (HOCl) has long been associated with a number of inflammatory diseases in mammalian bodies, the functions of HOCl in specific organs at abnormal conditions, such as liver injury, remain unclear due to its high reactivity and the lack of effective methods for its detection. Herein, a unique Ir(III) complex-based chemosensor, Ir-Fc, was developed for highly sensitive and selective detection of HOCl. Ir-Fc was designed by incorporating a ferrocene (Fc) quencher to a Ir(III) complex through a HOCl-responsive linker. In the presence of HOCl, the fast cleavage of Fc moiety in less than 1 s led to the enhancement of photoluminescence (PL) and electrochemical luminescence (ECL), by which the concentration of HOCl was determined by both PL and ECL analysis. Taking advantages of excellent properties of Ir(III) complexes, optical and electrochemical analyses of the response of Ir-Fc towards HOCl were fully investigated. Followed by the measurements of low cytotoxicity of Ir-Fc by MTT analysis, one-photon (OP), two-photon (TP) and lifetime imaging experiments were conducted to visualise the generation of HOCl in live microphage and HepG2 cells, and in zebrafish and mouse, respectively. Furthermore, the generation and distribution of HOCl in liver cells and liver injury of zebrafish and mouse were investigated. The results demonstrated the applicability of Ir-Fc as an effective chemosensor for imaging of HOCl generation in mitochondria of cells and liver injury in vivo, implying the potential of Ir-Fc for biomedical diagnosis and monitoring applications. © 2016 Elsevier B.V.

  • 374.
    Zhang, Fan
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Brinck, Tore
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Brandner, Birgit
    Claesson, Per M.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Dédinaité, Andra
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Pan, Jinshan
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    In situ confocal Raman micro-spectroscopy and electrochemical studies of mussel adhesive protein and ceria composite film on carbon steel in salt solutions2013In: Electrochimica Acta, ISSN 0013-4686, E-ISSN 1873-3859, Vol. 107, p. 276-291Article in journal (Refereed)
    Abstract [en]

    Thin films composed of Mefp-1 and ceria nanoparticles have shown an increasing corrosion inhibition effect with time for carbon steel in acidic aqueous solutions containing phosphate, which motivates a detailed study of the inhibition mechanism by in situ confocal Raman micro-spectroscopy (CRM) and electrochemical impedance spectroscopy (EIS) measurements. The presence of both CeO2 and ferric oxides in the thin composite film was demonstrated by X-ray photoelectron spectroscopy analysis. The Raman spectra assisted by DFT calculations suggest that Mefp-1 forms tri-Fe3+/Mefp-1 complexes and binds to ceria nanoparticles in the composite film. The in situ CRM measurement allow us to follow the development of corrosion products. The measurements show a mixture of Fe oxides/oxyhydroxides, and also indicate that ferrous oxides may be further oxidized by the composite film. Moreover, phosphate ions react with the Fe ions released from the surface to form iron-phosphate deposits, which become incorporated into the corrosion product layer and the composite film. The EIS measurements suggest a layered surface structure formed by the initial Mefp-1/ceria composite layer and the corrosion products/iron-phosphate deposits. These measurements also demonstrate the greatly increased inhibition effect of the composite film in the presence of the phosphate ions. The consistent CRM and EIS results suggest that the iron-phosphate deposits heal defects in the composite film and corrosion product layer, which results in a significantly improved corrosion inhibition of the Mefp-1/ceria composite film during initial and long term exposure.

  • 375.
    Zhang, Fan
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Pan, Jinshan
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Claesson, Per Martin
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Brinck, Tore
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Electrochemical, atomic force microscopy and infrared reflection absorption spectroscopy studies of pre-formed mussel adhesive protein films on carbon steel for corrosion protection2012In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 520, no 24, p. 7136-7143Article in journal (Refereed)
    Abstract [en]

    Electrochemical measurements, in situ and ex situ atomic force microscopy (AFM) experiments and infrared reflection absorption spectroscopy (IRAS) analysis were performed to investigate the formation and stability as well as corrosion protection properties of mussel adhesive protein (Mefp-1) films on carbon steel, and the influence of cross-linking by NaIO 4 oxidation. The in situ AFM measurements show flake-like adsorbed protein aggregates in the film formed at pH 9. The ex situ AFM images indicate multilayer-like films and that the film becomes more compact and stable in NaCl solution after the cross-linking. The IRAS results reveal the absorption bands of Mefp-1 on carbon steel before and after NaIO 4 induced oxidation of the pre-adsorbed protein. Within a short exposure time, a certain corrosion protection effect was noted for the pre-formed Mefp-1 film in 0.1 M NaCl solution. Cross-linking the pre-adsorbed film by NaIO 4 oxidation significantly enhanced the protection efficiency by up to 80%.

  • 376.
    Zhang, Fan
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Sababi, Majid
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Brinck, Tore
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Persson, Dan
    Pan, Jinshan
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Claesson, Per M.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science. SP Technical Research Institute of Sweden, Chemistry, Materials and Surfaces.
    In situ investigations of Fe3+ induced complexation of adsorbed Mefp-1 protein film on iron substrate2013In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 404, p. 62-71Article in journal (Refereed)
    Abstract [en]

    A range of in situ analytical techniques and theoretical calculations were applied to gain insights into the formation and properties of the Mefp-I film on iron substrate, as well as the protein complexation with Fe3+ ions. Adsorption kinetics of Mefp-1 and the complexation were investigated using QCM-D. The results suggest an initially fast adsorption, with the molecules oriented preferentially parallel to the surface, followed by a structural change within the film leading to molecules extending toward solution. Exposure to a diluted FeCl3 solution results in enhanced complexation within the adsorbed protein film, leading to water removal and film compaction. In situ Peak Force Tapping AFM was employed for determining morphology and nano-mechanical properties of the surface layer. The results, in agreement with the QCM-D observations, demonstrate that addition of Fe-3 induces a transition from an extended and soft protein layer to a denser and stiffer one. Further, in situ ATR-FTIR and Confocal Raman Micro-spectroscopy (CRM) techniques were utilized to monitor compositional/structural changes in the surface layer due to addition of Fe3+ ions. The spectroscopic analyses assisted by DFT calculations provide evidence for formation of tri-Fe3+/catechol complexes in the surface film, which is enhanced by Fe3+ addition.

  • 377. Zhang, H. -Q
    et al.
    Akram, N.
    Skog, P.
    Soroka, Inna
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Trautmann, C.
    Schuch, R.
    Tailoring of keV-ion beams by image charge when transmitting through rhombic and rectangular shaped nanocapillaries2012In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 108, no 19, p. 193202-Article in journal (Refereed)
    Abstract [en]

    We report on an unexpected effect of tailoring transmission profiles of Ne7 + ions through nanocapillaries of rhombic and rectangular cross sections in mica. We find that capillaries of rhombic cross sections produce rectangular shaped ion transmission profiles and, vice versa, that capillaries of rectangular geometry give a rhombic beam shape. This shaping effect only occurs for transmitted ions and is absent for the small fraction of neutralized particles. The experimental findings and simulations of the projectile trajectories give clear evidence that the observed effect is due to the image forces experienced by the transmitting ions. This novel beam shaping mechanism suggests applications for the guiding, focusing, and shaping of ion beams.

  • 378. Zhang, J.
    et al.
    Hua, Yong
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Xu, Bo
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Yang, L.
    Liu, Peng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Johansson, M. B.
    Vlachopoulos, N.
    Kloo, Lars
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Boschloo, G.
    Johansson, E. M. J.
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Hagfeldt, A.
    The Role of 3D Molecular Structural Control in New Hole Transport Materials Outperforming Spiro-OMeTAD in Perovskite Solar Cells2016In: Advanced Energy Materials, ISSN 1614-6832, Vol. 6, no 19, article id 1601062Article in journal (Refereed)
  • 379. Zhang, Jinbao
    et al.
    Xu, Bo
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Johansson, Malin B.
    Hadadian, Mahboubeh
    Baena, Juan Pablo Correa
    Liu, Peng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Hua, Yong
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Vlachopoulos, Nick
    Johansson, Erik M. J.
    Boschloo, Gerrit
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Hagfeldt, Anders
    Constructive Effects of Alkyl Chains: A Strategy to Design Simple and Non-Spiro Hole Transporting Materials for High-Efficiency Mixed-Ion Perovskite Solar Cells2016In: ADVANCED ENERGY MATERIALS, ISSN 1614-6832, Vol. 6, no 13, article id 1502536Article in journal (Refereed)
  • 380. Zhang, Jinbao
    et al.
    Xu, Bo
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA.
    Yang, Li
    Ruan, Changqing
    Wang, Linqin
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Liu, Peng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Zhang, Wei
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Vlachopoulos, Nick
    Kloo, Lars
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Boschloo, Gerrit
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. State Key Laboratory of Fine Chemicals, DUT-KTH Joint Education and Research Center on Molecular Devices, Dalian University of Technology (DUT), Dalian, China.
    Hagfeldt, Anders
    Johansson, Erik M. J.
    The Importance of Pendant Groups on Triphenylamine-Based Hole Transport Materials for Obtaining Perovskite Solar Cells with over 20% Efficiency2018In: ADVANCED ENERGY MATERIALS, ISSN 1614-6832, Vol. 8, no 2, article id 1701209Article in journal (Refereed)
    Abstract [en]

    Tremendous progress has recently been achieved in the field of perovskite solar cells (PSCs) as evidenced by impressive power conversion efficiencies (PCEs); but the high PCEs of >20% in PSCs has so far been mostly achieved by using the hole transport material (HTM) spiro-OMeTAD; however, the relatively low conductivity and high cost of spiro-OMeTAD significantly limit its potential use in large-scale applications. In this work, two new organic molecules with spiro[fluorene-9,9-xanthene] (SFX)-based pendant groups, X26 and X36, have been developed as HTMs. Both X26 and X36 present facile syntheses with high yields. It is found that the introduced SFX pendant groups in triphenylamine-based molecules show significant influence on the conductivity, energy levels, and thin-film surface morphology. The use of X26 as HTM in PSCs yields a remarkable PCE of 20.2%. In addition, the X26-based devices show impressive stability maintaining a high PCE of 18.8% after 5 months of aging in controlled (20%) humidity in the dark. We believe that X26 with high device PCEs of >20% and simple synthesis show a great promise for future application in PSCs, and that it represents a useful design platform for designing new charge transport materials for optoelectronic applications.

  • 381. Zhang, Jinbao
    et al.
    Yang, Lei
    Shen, Yang
    Park, Byung-Wook
    Hao, Yan
    Johansson, Erik M. J.
    Boschloo, Gerrit
    Kloo, Lars
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Gabrielsson, Erik
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Jarboui, Adel
    Perruchot, Christian
    Jouini, Mohamed
    Vlachopoulos, Nick
    Hagfeldt, Anders
    Poly(3,4-ethylenedioxythiophene) Hole-Transporting Material Generated by Photoelectrochemical Polymerization in Aqueous and Organic Medium for All-Solid-State Dye-Sensitized Solar Cells2014In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 118, no 30, p. 16591-16601Article in journal (Refereed)
    Abstract [en]

    We applied organic donor-pi-acceptor (D-pi-A) sensitizers for photoelectrochemical polymerization (PEP) because of their appropriate energy levels and high light absorption. The polymerized conducting polymer PEDOT was used as hole conductor in all-solid-state dye-sensitized solar cells (ssDSCs). By combination of the D-pi-A sensitizers and the generated PEDOT from PEP of bis-EDOT in acetonitrile, the resulting device showed an average power conversion efficiency of 5.6%. Furthermore, the PEP in aqueous micellar electrolytic medium was also employed because of the ability to decrease oxidation potential of the precursor, thereby making the polymerization process easier. The latter method is a cost-effective and environmentally friendly approach. Using as hole conductor the so-obtained PEDOT from PEP of bis-EDOT in aqueous electrolyte, the devices exhibited impressive power conversion efficiency of 5.2%. To compare the properties of the generated polymer from bis-EDOT in these two PEP methods, electron lifetime, photoinduced absorption (PIA) spectra, and UV-vis-NIR spectra were measured. The results showed that PEDOT from organic PEP exhibits a delocalized conformation with high conductivity and a smooth and compact morphology; a rough morphology with high porosity and polymer structure of relatively shorter chains was assumed to be obtained from aqueous PEP. Therefore, better dye regeneration but faster charge recombination was observed in the device based on PEDOT from aqueous PEP of bis-EDOT. Subsequently, to extend the aqueous PEP approach in consideration of the ability to decrease the oxidation potential of the precursor, the easily available precursor EDOT was for the first time used for PEP in aqueous medium in a variant of the aforementioned procedure, and the device based on the so-obtained PEDOT shows a more than 70-fold increase in efficiency, 3.0%, over that based on the polymer generated from EDOT by PEP in organic media. It was demonstrated that aqueous micellar PEP with EDOT as monomer is an efficient strategy for generation of conducting polymer hole-transporting materials.

  • 382. Zhang, W.
    et al.
    Zhang, F.
    Wang, Yong-Lei
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Song, B.
    Zhang, R.
    Yuan, J.
    Red-Emitting Ruthenium(II) and Iridium(III) Complexes as Phosphorescent Probes for Methylglyoxal in Vitro and in Vivo2017In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 56, no 3, p. 1309-1318Article in journal (Refereed)
    Abstract [en]

    Transition-metal complexes, ruthenium(II) and iridium(III) complexes in particular, with fascinating triplet emissions are rapidly emerging as important phosphorescent dyes for application in the sensing and imaging of biological makers in live cells and organisms. In this contribution, two red-emitting transition-metal complexes, [Ru(bpy)2(DA-phen)](PF6)2 and [Ir(ppy)2(DA-phen)](PF6) (bpy = 2,2′-bipyridine, DA-phen = 4,5-diamino-1,10-phenanthroline, and ppy = 2-phenylpyridine), were designed and synthesized as phosphorescent probes for the highly sensitive and selective detection of methylglyoxal (MGO), an essential biomarker in the etiopathogenesis of several diseases. Both probes showed weak emissions in aqueous media because of the existence of an effective photoinduced-electron-transfer process, while their emissions could be remarkably enhanced upon the addition of MGO. The photophysical and electrochemical properties, as well as phosphorescent responses of the probes toward MGO, were examined. The ground- and excited-state properties of the probes and their reaction products with MGO, [Ru(bpy)2(MP-phen)](PF6)2 and [Ir(ppy)2(MP-phen)](PF6) (MP-phen = 2-methylpyrazino-1,10-phenanthroline), the sensing mechanism, and several important experimental facts were investigated and validated using density functional theory (DFT)/time-dependent DFT computations. The results indicated that the phosphorescence switch-ON is due to the elimination of electron transfer and followed the reestablishment of emissive triplet excited states. To evaluate the feasibility of [Ru(bpy)2(DA-phen)](PF6)2 and [Ir(ppy)2(DA-phen)](PF6) as bioprobes, their cytotoxicity was examined, and their applicability for visualizing intracellular and in vivo MGO was demonstrated.

  • 383.
    Zhang, Wei
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Franzen, Johan.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Asymmetric catalytic synthesis of corynanthe and ipecac alkaloids2012In: Targets in Heterocyclic Systems: Chemistry and Properties / [ed] Orazio A. Attanasi; Domenico Spinelli, Societa Chimica Italiana , 2012, p. 31-55Chapter in book (Refereed)
    Abstract [en]

    Corynanthe and ipecac alkaloids constitute a large group of natural occurring alkaloids that demonstrate a vast variety of bioactivity and have a long history of usage as herbal drugs. Both the corynanthe and ipecac alkaloids share a common structural unit with a quinolizidine ring fused with a benzo- or indolo-group and three stereocentres wherein one is a ring-junction stereocentre. From synthetic point of view, these natural products represent an intriguing challenge and over the years several strategies toward the asymmetric total synthesis of corynanthe and ipecac alkaloids have been devised and the majority of these are target specific natural-pool based strategies. However, during the last few years, several efficient and diverse strategies based on asymmetric catalysis and one-pot cascade protocols as the key-steps have emerged. In this mini-review the attention is to give an overview of these strategies.

  • 384.
    Zhang, Wei
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Liu, Peng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Sadollahkhani, Azar
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Li, Yuanyuan
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Zhang, Biaobiao
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Zhang, Fuguo
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Safdari, Majid
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Hao, Yan
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Hua, Yong
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Kloo, Lars
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Investigation of Triphenylamine (TPA)-Based Metal Complexes and Their Application in Perovskite Solar Cells2017In: ACS OMEGA, ISSN 2470-1343, Vol. 2, no 12, p. 9231-9240Article in journal (Refereed)
    Abstract [en]

    Triphenylamine-based metal complexes were designed and synthesized via coordination to Ni(II), Cu(II), and Zn(II) using their respective acetate salts as the starting materials. The resulting metal complexes exhibit more negative energy levels (vs vacuum) as compared to 2,2', 7,7'-tetrakis(N, N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (Spiro-OMeTAD), high hole extraction efficiency, but low hole mobilities and conductivities. Application of dopants typically used for Spiro-OMeTAD was not successful, indicating a more complicated mechanism of partial oxidation besides the redox potential. However, utilization as hole-transport material was successful, giving a highest efficiency of 11.1% under AM 1.5G solar illumination.

  • 385.
    Zhang, Yan
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Vongvilai, Pornrapee
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Sakulsombat, Morakot
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Fischer, Andreas
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Ramström, Olof
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Asymmetric Synthesis of Substituted Thiolanes through Domino Thia-Michael-Henry Dynamic Covalent Systemic Resolution using Lipase Catalysis2014In: Advanced Synthesis and Catalysis, ISSN 1615-4150, E-ISSN 1615-4169, Vol. 356, no 5, p. 987-992Article in journal (Refereed)
    Abstract [en]

    Dynamic systems based on consecutive thia-Michael and Henry reactions were generated and transformed using lipase-catalyzed asymmetric transformation. Substituted thiolane structures with three contiguous stereocenters were resolved in the process in high yields and high enantiomeric excesses.

  • 386. Zietz, Burkhard
    et al.
    Gabrielsson, Erik
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Johansson, Viktor
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    El-Zohry, Ahmed M.
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Kloo, Lars
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Photoisomerization of the cyanoacrylic acid acceptor group - a potential problem for organic dyes in solar cells2014In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 16, no 6, p. 2251-2255Article in journal (Refereed)
    Abstract [en]

    Organic solar cell dyes containing the most common anchoring group, cyanoacrylic acid, are shown to be photolabile and undergo photoisomerization. This may have significant consequences for dye-sensitized solar cells, as isomerisation competes with electron injection and leads to modifications of the dye and surface arrangement.

  • 387. Zubkov, M.
    et al.
    Stait-Gardner, T.
    Price, W. S.
    Stilbs, Peter
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Steady state effects in a two-pulse diffusion-weighted sequence2015In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 142, no 15, article id 154201Article in journal (Refereed)
    Abstract [en]

    In conventional nuclear magnetic resonance (NMR) diffusion measurements a significant amount of experimental time is used up by magnetization recovery, serving to prevent the formation of the steady state, as in the latter case the manifestation of diffusion is modulated by multiple applications of the pulse sequence and conventional diffusion coefficient inference procedures are generally not applicable. Here, an analytical expression for diffusion-related effects in a two-pulse NMR experiment (e.g., pulsed-gradient spin echo) in the steady state mode (with repetition times less than the longitudinal relaxation time of the sample) is derived by employing a Fourier series expansion within the solution of the Bloch-Torrey equations. Considerations are given for the transition conditions between the full relaxation and the steady state experiment description. The diffusion coefficient of a polymer solution (polyethylene glycol) is measured by a two-pulse sequence in the full relaxation mode and for a range of repetition times, approaching the rapid steady state experiment. The precision of the fitting employing the presented steady state solution by far exceeds that of the conventional fitting. Additionally, numerical simulations are performed yielding results strongly supporting the proposed description of the NMR diffusion measurements in the steady state.

  • 388.
    Åkerstedt, Josefin
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Subvalent Cluster Compounds and Synthesis in Alternative Reaction Media2012Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    With the aim of finding alternative reaction media for the synthesis of subvalent main group and transition metal cluster compounds, traditionally made through solid state reactions or in superacidic media, different alternative reaction media have been explored in this work. Room-temperature ionic liquids are amongst the more unconventional reaction media used. The syntheses performed have been aimed at both anionic and cationic cluster and the main tools used for characterization have been different X-ray diffraction and spectroscopic techniques.

    Selected ionic liquids have along with dichloromethane been shown to work as alternative reaction media for room temperature synthesis of the Bi5[GaCl4]3 salt. The salt containing the subvalent naked bismuth polycation Bi5 3+ was isolated from reduction reactions of BiCl3 in Ga/GaCl3-dichloromethane respectively Ga/GaCl3-ioinc liquid media. Three different classes of ionic liquids based on phosphonium-, imidazolium- and pyrrolidinium- salts have been used in synthesis. Homopolyatomic clusters from the lighter Group 15 element arsenic have also been studied. Solutions from the oxidative and reductive reaction routes of arsenic and AsCl3 in Lewis acidic toluene media were studied by EXAFS spectroscopy. The results were evaluated using molecular dynamics simulations of arsenic clusters. A discussion on how the calculated As4 cluster model relates to the experimental data resulted from this study.

    In terms of homopolyatomic anionic clusters the [K+(2,2,2-crypt)]2Ge9 2- compound containing the naked Ge9 2- anionic cluster has been isolated. The crystallographic investigation of [K+(2,2,2-crypt)]2Ge9 2- shows Zintl cluster anion Ge9 2- to be tricapped trigonal-prismatic with a symmetry very close to D3h. A chemical bonding analysis reveals two local minima of D3h symmetry and the cluster interaction scheme to be based on highly delocalised bonding.

    Ligand supported transition metal clusters from tungsten and palladium have also been prepared. Reduction of WCl6 in a reaction mixture of ionic liquid and co-solvent toluene resulted in tritungsten decachloride; W3Cl10(MeCN)3, being formed. Furthermore, palladium sandwich compounds; [Pd2(Ga2Cl7)(C7H8)2], [Pd2(GaCl4)(C9H12)2]∙C9H12 and [Pd2(Ga2Cl7)(C6H5Cl)2] have been prepared using GaCl3-arene reaction media.

  • 389.
    Åkerstedt, Josefin
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Gorlov, Mikhail
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Kloo, Lars
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Room-Temperature Synthesis of the Bi-5[GaCl4](3) Salt From Three Different Classes of Ionic Liquids2013In: Journal of cluster science, ISSN 1040-7278, E-ISSN 1572-8862, Vol. 24, no 1, p. 157-164Article in journal (Refereed)
    Abstract [en]

    Following the development in the synthesis of subvalent cluster compounds, we report on the use of three different classes of room-temperature ionic liquids for the synthesis of the pentabismuth-tris(tetragallate) salt, Bi-5[GaCl4](3), characterized by X-ray diffraction. The Bi-5[GaCl4](3) salt was prepared by reduction of BiCl3 using gallium metal in ionic liquid reaction media containing a strong Lewis acid, GaCl3. The ionic liquids; trihexyltetradecyl phosphonium chloride [Th-Td-P+]Cl-, 1-dodecyl-3-methylimidazolium chloride [Dod-Me-Im(+)]Cl- and N-butyl-N-methylpyrrolidinium chloride [Bu-Me-Pyrr(+)]Cl- from three of the main classes of ionic liquids were used in synthesis. Reactions using ionic liquids composed of the trihexyltetradecyl phosphonium cation [Th-Td-P+] and the anions; tetrafluoroborate [BF4 (-)], bis(trifluoro-methyl sulfonyl) imide [(Tf)(2)N-] and hexafluorophosphate [PF6 (-)] were also investigated.

  • 390.
    Åkerstedt, Josefin
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Rosdahl, Jan
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Persson, Per
    Umeå University.
    Kloo, Lars
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Arsenic Clusters in Solution: An Experimental and A Priori Theoretical EXAFS StudyManuscript (preprint) (Other academic)
  • 391.
    Åkerstedt, Josefin
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Ruck, M.
    Kloo, Lars
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Long, J. R.
    Tungsten Chloride W3Cl10(CH3CN)3 fromRoom-temperature Synthesis in Ionic liquid using an Organic Co-solventManuscript (preprint) (Other academic)
  • 392.
    Öberg, Helena
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Brinck, Tore
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Fragment molecular orbital study of the cAMP-dependent protein kinase catalyzed phosphoryl transfer: a comparison with the differential transition state stabilization method2016In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 18, no 22, p. 15153-15161Article in journal (Refereed)
    Abstract [en]

    The importance of key residues to the activity of the cAMP-dependent protein kinase catalyzed phosphoryl transfer and to the stabilization of the transition state of the reaction has been investigated by means of the fragment molecular orbital (FMO) method. To evaluate the accuracy of the method and its capability of fragmenting covalent bonds, we have compared stabilization energies due to the interactions between individual residues and the reaction center to results obtained with the differential transition state stabilization method (Szarek, et al., J. Phys. Chem. B, 2008, 112, 11819-11826) and observe, despite a size difference in the fragment describing the reaction center, near-quantitative agreement. We have also computed deletion energies to investigate the effect of virtual deletion of key residues on the activation energy. These results are consistent with the stabilization energies and yield additional information as they clearly capture the effect of secondary interactions, i. e. interactions in the second coordination layer of the reaction center. We find that using FMO to calculate deletion energies is a powerful and time efficient approach to analyze the importance of key residues to the activity of an enzyme catalyzed reaction.

5678 351 - 392 of 392
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