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  • 1.
    Belda, Oscar
    et al.
    KTH, Tidigare Institutioner, Kemi.
    Duquesne, Sophie
    KTH, Tidigare Institutioner, Kemi.
    Fischer, A.
    Moberg, Christina
    KTH, Tidigare Institutioner, Kemi.
    Chiral bispyridylamide metal complexes as catalysts for the enantioselective adddition of TMSCN to aldehydes2004Ingår i: Journal of Organometallic Chemistry, ISSN 0022-328X, E-ISSN 1872-8561, Vol. 689, nr 23, s. 3750-3755Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The use of (1R,2R)-N,N'-bis(2-pyridinecarboxyamido)-1,2-diphenylethane metal complexes as catalysts for the enantioselective addition of trimethylsilyl cyanide to aldehydes is described. Enantioselectivities up to 70% ee were obtained with a Ti(IV) catalyst. Complexes with Zr(IV), Sc(III), Yb(III) and Cu(II) afforded less selective catalysts. For the Zr(IV) complex, a rate and selectivity enhancement was observed when adding 0.5 equiv. of water with respect to the catalyst. Studies of the metal complexes involved in the reaction were carried out by means of H-1 NMR spectroscopy. A Zr complex was shown by X-ray crystallography to exhibit distorted octahedral coordination, with the four nitrogen atoms of the doubly deprotonated ligand essentially in one plane.

  • 2. Gao, Weiming
    et al.
    Liu, Jianhui
    Akermark, Bjoern
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Facile and highly efficient light-induced PR3/CO ligand exchange: A novel approach to the synthesis of (mu-(SCH2NPrCH2S)-Pr-n)Fe-2(CO)(4)(PR3)(2)2007Ingår i: Journal of Organometallic Chemistry, ISSN 0022-328X, E-ISSN 1872-8561, Vol. 692, nr 7, s. 1579-1583Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A straightforward and efficient transformation of the Fe-S complex [(mu-SCH2NPrCH2S)Fe-2(CO)(6)] to its double phosphine coordinated analogues [(mu-(SCH2NPrCH2S)-Pr-n)Fe-2(CO)(4)(PR3)(2)] (R = Ph, Me) is described. The single crystal structure of the PPh3-disubstituted Complex [(mu-(SCH2NPrCH2S)-Pr-n)Fe-2(CO)(4)(Ph3P)(2)] (3) showed that both of the phosphine ligands take an apical/apical instead of a basal/ basal or an apical/basal configuration.

  • 3.
    Gerdin, Martin
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Penhoat, Maël
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Zalubovskis, Raivis
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Pétermann, Claire
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Moberg, Christina
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Enantioselective silicon-boron additions to cyclic 1,3-dienes catalyzed by the platinum group metal complexes2008Ingår i: Journal of Organometallic Chemistry, ISSN 0022-328X, E-ISSN 1872-8561, Vol. 693, nr 23, s. 3519-3526Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Silaborations of 1,3-cyclohexadiene and 1,3-cycloheptadiene were achieved using catalysts prepared from different combinations of phosphorus ligands and group 10 metal compounds. For the six-membered compound, 1,4-adducts with up to 82% ee were obtained employing Pt(0) and phosphoramidite ligands. For the seven-membered diene optimal conditions were found using catalysts based on Ni(0), but the highest selectivity observed was merely 22% ee. No improvement of the chiral induction was obtained using chiral silylboranes in combination with chiral phosphoramidite ligands in the additions to 1,3-cyclohexadiene. The adduct obtained from cyclohexadiene was used in allylborations of aldehydes under microwave irradiation to produce homoallylic alcohols with moderate to good diastereoselectivity.

  • 4.
    Gorlov, Mikhail
    et al.
    KTH, Tidigare Institutioner, Kemi.
    Fischer, Andreas
    KTH, Tidigare Institutioner, Kemi.
    Kloo, Lars A.
    KTH, Tidigare Institutioner, Kemi.
    Reaction between palladium(II) and gallium(III) halogenides in arenes: influence of halogen nature on the formation of binuclear palladium(I) clusters2004Ingår i: Journal of Organometallic Chemistry, ISSN 0022-328X, E-ISSN 1872-8561, Vol. 689, nr 2, s. 489-492Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Palladium(II) bromide reacts with gallium(III) bromide in the presence of arenes yielding binuclear palladium(l) complexes [Pd-2(GaBr4)(2)(arene)(2)], where arene = benzene (1), toluene (2) and p-xylene (3). Reaction of palladium(II) chloride with gallium(III) chloride in p-xylene leads to the analogous palladium(l) compound [Pd-2(GaCl4)(2)(p-xylene)(2)] (4); the X-ray structures of 1-4 were determined.

  • 5. Hülsen, M.
    et al.
    Norman, P.
    Dolg, M.
    Theoretical investigation of thermally and photochemically induced haptotropic rearrangements of chromium ligands on naphthalene systems2011Ingår i: Journal of Organometallic Chemistry, ISSN 0022-328X, E-ISSN 1872-8561, Vol. 696, nr 24, s. 3861-3866Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The description of chemical reactions by means of quantum mechanical methods is an important task and gets even more challenging if excited states have to be considered. This work focuses on the haptotropic rearrangements of chromium atoms bearing three coligands which migrate on a naphthalene-like system. The reactions are either thermally or photochemically controllable and thus the systems are candidates for molecular switches. We propose a detailed reaction scheme for the investigated system. Furthermore, we provide a detailed analysis of the important steps of the reaction cycle. In comparison to previous publications, the scope of this work also involves the quantum mechanical treatment of excited states in order to describe occurring photon absorption processes in a proper way. Linear response time-dependent density functional theory calculations were carried out to describe the molecules' responses to the external electromagnetic perturbations. © 2011 Elsevier B.V. All rights reserved.

  • 6. Johansson, A
    et al.
    Wingstrand, Erica
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Hakansson, M
    Chiral diethylzinc complexes with diamine ligands: synthesis, crystal structure and enantioselective solvent-free alkylation2005Ingår i: Journal of Organometallic Chemistry, ISSN 0022-328X, E-ISSN 1872-8561, Vol. 690, nr 16, s. 3846-3853Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In search for conglomerates of stereochemically labile organometallic reagents, three new complexes between diethylzinc and diamine ligands have been synthesized and structurally characterized by single-crystal X-ray diffraction methods. Ligands include N,N,N',N'-tetraethylethylenediamine (teeda), N-isopropyl-N,N',N'-trimethylethylenediamine (itmeda), and (-)-sparteine (spa). Diethylzinc forms monomeric complexes, exhibiting a distorted tetrahedral coordination geometry around zinc in all three complexes, viz. [ZnEt(2)(teeda)] (1), [ZnEt(2)(itmeda)] (2), and [ZnEt(2)(spa)] (3). Both 1 and 2 are stereochemically labile and exhibit chiral complexes, displaying different types of conformational chirality, but they form racemic crystals. By using the chiral crystals of 3 in a nucleophilic addition to benzaldehyde in the absence of solvent at low temperature, an increase in ee from approximately 8 to 10% was obtained (compared to the same reaction in solution). It thus seems feasible, not only to retain the enantioselectivity obtained in solution, but perhaps even to increase the ee by using solventless reactions.

  • 7. Kaiser, N. F. K.
    et al.
    Bremberg, U.
    Larhed, M.
    Moberg, Christina
    KTH, Tidigare Institutioner                               , Kemi.
    Hallberg, A.
    Microwave-mediated palladium-catalyzed asymmetric allylic alkylation; an example of highly selective fast chemistry2000Ingår i: Journal of Organometallic Chemistry, ISSN 0022-328X, E-ISSN 1872-8561, Vol. 603, nr 1, s. 2-5Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Highly enantioselective palladium-catalyzed microwave-mediated fast chemistry has been performed on dimethyl malonate alkylation of(rac)-1,3-diphenylallyl-1-acetate (1). Utilizing the recently developed palladium-phosphineoxazoline catalytic system, with general stability at elevated temperatures (less than or equal to 145 degrees C), quantitative yields of greater than or equal to 97% and ee values of up to >99% were obtained after very short irradiation times (15-300 s, TOF up to 7000 h(-1)).

  • 8. Li, Cheng
    et al.
    Wang, Mei
    Pan, Jingxi
    Zhang, Pan
    Zhang, Rong
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Photochemical hydrogen production catalyzed by polypyridyl ruthenium-cobaloxime heterobinuclear complexes with different bridges2009Ingår i: Journal of Organometallic Chemistry, ISSN 0022-328X, E-ISSN 1872-8561, Vol. 694, nr 17, s. 2814-2819Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Two heterobinuclear complexes [(bpy)(2)Ru(bpy-4-CH3,4'-CONH(4-py)Co(dmgBF(2))(2)(OH2)](PF6)(2) (1, dmgBF(2) = (difluoroboryl) dimethylglyoximato) and [(bpy)(2)Ru(bpy-4-CH3,4'-CONHCH2(4-py)Co(dmgBF(2))(2)(OH2)](PF6)(2) (2) were prepared, in which the polypyridyl ruthenium photosensitizer and the cobaloxime catalyst are connected either by a conjugated bridge (1) or by an unconjugated one (2). Complexes 1 and 2 were used as photocatalysts for hydrogen generation. Under optimal conditions, the turnover numbers (ton) for hydrogen evolution were 38 for 1 and 48 for 2 in the presence of 300 equiv of both Et3N and [Et3NH][BF4] in the acetone solution during an 8-h irradiation of visible light (lambda > ca. 400 nm). The complex 2 with an unconjugated bridge proved to be more efficient for photochemical hydrogen generation than the complex 1 with a conjugated bridge under the same reaction condition.

  • 9. Li, Minna
    et al.
    Liu, Jianhui
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Pan, Jingxi
    Zhao, Changzhi
    Oligo thiophene-2-yl-vinyl bridged mono- and binuclear ruthenium(II) tris-bipyridine complexes: Synthesis, photophysics, electrochemistry and electrogenerated chemiluminescence2008Ingår i: Journal of Organometallic Chemistry, ISSN 0022-328X, E-ISSN 1872-8561, Vol. 693, nr 1, s. 46-56Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A series of mono- and binuclear ruthenium(II) tris-bipyridine complexes tethered to oligothienylenevinyleries have been synthesized and characterized by H-1 NMR, C-13 NMR and TOF-MS spectrometry. Photophysics, electrochemistry and electrogenerated chemiluminescence (ECL) properties of these complexes are investigated. The electronic absorption spectra of the mononuclear ruthenium complexes show a significant red shift both at MLCT (metal-to-ligand charge transfer) and pi-pi* transitions of oligothienylenevinylenes with increase in the number of thiophenyl-2-yl-vinyl unit. For the binuclear complexes these two absorption bands are overlapped.) All the metal complexes have very weak emission compared to that of the reference complex Ru(bpy)(3)(2+). The first reduction potentials of all mononuclear ruthenium complexes are less negative than that of Ru(bpy)(3)(2+), due to the moderate electron-withdrawing effect of oligothienylenevinylenes. For binuclear ruthenium complexes, only one Ru(II/III) oxidation peak (E-1/2=0.96V vs. Ag/Ag+) was observed, suggesting a weak interaction between two metal centers. Three successive reduction processes of bipyridine ligands are similar among all ruthenium complexes except for RuTRu, which has a very sharp peak owing to the accumulation of neutral product oil the electrode surface. All these ruthenium complexes exhibited different ECL property in CH3CN solution without any additional reductant or oxidant. For three mononuclear ruthenium complexes, the ECL intensity strengthens with increase in the number of thiophene-2-yl-vinyl unit. However, the ECL efficiency dramatically decreased in the binuclear ruthenium complexes. The ECL efficiencies of all the)2+, reported complexes do not exceed that of Ru(bpy 3 where the ECL efficiency decreases in the order of RuTRu > Ru3T > Ru2T > RuT > Ru2TRu (RuT, bis-2,2'-bipyridyl-(4-metliyl-4'-(2-thienylethenyl)-2,2'-bipyridine) ruthenium dihexafluorophosphate; Ru2T, bis-2,2'-bipyridyl-(4-methyl-4'-{(E) -2-[5-((E) -2-thienylethenyl)-thienylethenyl])-2,2'-bipyridine)ruthenium dihexafluorophosphate; Ru3T, bis-2,2'-bipyridyl-(4-methyl-4'-[(E)-2-{(E)-2-[5-((E)-2-thienylethenyl)- thienylethenyl])}-2,2'-bipyridine) ruthenium dihexafluorophosphate; RuTRu, bis-2,2'-bipyridyl-ruthenium-bis-[2-((E)-4'-methyl-2,2'-bipyridinyl-4)-e thenyl]-thienyl-bis-2,2'-bipyridyl-ruthenium tetrahexafluorophosphate; Ru2TRu, bis-2,2'-bipyridyl-ruthenium-(E)-1,2-bis-{2-[2-((E)-4'-methyl-2,2'-bipyr idinyl-4)-ethenyl]-thienyl}ethenyl-bis-2,2'-bipyridyl-ruthenium tetrahexafluorophosphate).

  • 10. Li, Minna
    et al.
    Liu, Jianhui
    Zhao, Changzhi
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Aryl-diamide bridged binuclear ruthenium(II) tris(bipyridine) complexes: Synthesis, photophysical, electrochemical and electrochemiluminescence properties2006Ingår i: Journal of Organometallic Chemistry, ISSN 0022-328X, E-ISSN 1872-8561, Vol. 691, nr 20, s. 4189-4195Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Several new symmetrical aromatic hydrocarbon bridged bipyridine ligands and their binuclear Ru (II) complexes have been designed, synthesized and characterized on the basis of H-1 NMR, MS and HRMS. Their absorption and emission properties, electrochemical behaviors and electrochemical luminescence were investigated. All ruthenium complexes show characteristic MLCT absorption and similar redox potential. Among the three complexes reported, 4c has the best electrochemical luminescence property.

  • 11. Na, Yong
    et al.
    Wang, Mei
    Jin, Kun
    Zhang, Rong
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    An approach to water-soluble hydrogenase active site models: Synthesis and electrochemistry of diiron dithiolate complexes with 3,7-diacetyl-1,3,7-triaza-5-phosphabicyclo 3.3.1 nonane ligand(s)2006Ingår i: Journal of Organometallic Chemistry, ISSN 0022-328X, E-ISSN 1872-8561, Vol. 691, nr 23, s. 5045-5051Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In order to improve the hydro- and protophilicity of the active site models of the Fe-only hydrogenases, three diiron dithiolate complexes with DAPTA ligand(s) (DAPTA=3,7-diacetyl-1,3,7-triaza-5-phosphabicyclo[3.3.1]nonanc), (mu-pdt)[Fe(CO)(2)][Fe(CO)(2)(DAPTA)] (1, pdt = 1,3-propanedithiolato), (mu-pdt)[Fe(CO)(2)(DAPTA)](2) (2) and (mu-pdt)[Fe(CO)(2)(PTA)][Fe(CO)(2)(DAPTA)] (3), were prepared and spectroscopically characterized. The water solubility of DAPTA-coordinate complexes 1-3 is better than that of the PTA-coordinate analogues. With complexes 1-3 as electrocatalysts, the overvoltage is reduced by 460-770 mV for proton reduction from acetic acid at low concentration in CH3CN. Significant decrease, up to 420 mV, in reduction potential for the Fe(I)Fe(I) to Fe(I)Fe(0) process and the curve-crossing phenomenon are observed in cyclic voltammograms of 2 and 3 in CH3CN/H2O mixtures. The introduction of the DAPTA ligand to the diiron dithiolate model complexes indeed makes the water solubility of 2 and 3 sufficient for electrochemical studies in pure water, which show that the proton reduction from acetic acid in pure water is electrochemically catalyzed by 2 and 3 at ca. -1.3 V vs. NHE.

  • 12. Ning, Zhijun
    et al.
    Zhang, Qiong
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Wu, Wenjun
    Tian, He
    Novel iridium complex with carboxyl pyridyl ligand for dye-sensitized solar cells: High fluorescence intensity, high electron injection efficiency?2009Ingår i: Journal of Organometallic Chemistry, ISSN 0022-328X, E-ISSN 1872-8561, Vol. 694, nr 17, s. 2705-2711Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Novel iridium-based sensitizers Iridium(III) bis[2-phenylpyridinato-N,C-2']-5-carboxylpicolinate) (Ir1), Iridium(III) bis[2-(naphthalen-1-yl) pyridinato-N,C-2']-5-carboxyl-picolinate) (Ir2), Iridium(III) bis[2-phenylpyridinato-N, C-2']-4,4'-(dicarboxylicacid)-2,2'-bipyridine (Ir3) were synthesized for sensitization of mesoscopic titanium dioxide injection solar cells. By changing the ligand, the absorption spectra can be extended and molar extinction coefficient was enhanced. The dye-sensitized nanocrystalline TiO2 solar cells (DSSCs) based on dye Ir3 showed the best photovoltaic performance: a maximum monochromatic incident photon-to-current conversion efficiency (IPCE) of 85%, a short-circuit photocurrent density (J(sc)) of 9.59 mA cm (2), an open-circuit photovoltage (V-oc) of 0.552 V, and a fill factor (ff) of 0.54, corresponding to an overall conversion efficiency of 2.86% under AM 1.5 sun light. Moreover, the HOMO and LUMO energy levels tuning can be conveniently accomplished by alternating the ligand. The high oxidative potential of Ir3 enables it to be used along with Br-/Br-3(-) redox electrolyte and the photovoltage was found to be enhanced greatly.

  • 13.
    Strand, Daniel
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Rein, Tobias
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    [(BINAP)Re(O)Cl-3] as an efficient catalyst for olefination of chiral alpha-substituted aliphatic aldehydes2010Ingår i: Journal of Organometallic Chemistry, ISSN 0022-328X, E-ISSN 1872-8561, Vol. 695, nr 19-20, s. 2220-2224Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A convenient one-pot preparation of [(BINAP) Re(O)Cl-3] (6) is described. This complex was demonstrated to be an efficient catalyst for the olefination of aldehydes by reaction with alpha-diazo esters, with essentially quantitative yields and up to 98:2 geometric selectivity. The potential for using enantiopure [(BINAP)Re(O)Cl-3] (6) to promote an asymmetric kinetic resolution of racemic alpha-stereogenic aldehydes was investigated, but no enantiotopic discrimination was observed. Control experiments indicate that this lack of selectivity stems from the in-situ formation of a phosphonium ylide, which accounts for product formation in a non-metal associated reaction pathway.

  • 14. Tran, Lien-Hoa
    et al.
    Eriksson, Lars
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Akermark, Bjorn
    A new square planar mononuclear Mn-III complex for catalytic epoxidation of stilbene2008Ingår i: Journal of Organometallic Chemistry, ISSN 0022-328X, E-ISSN 1872-8561, Vol. 693, nr 6, s. 1150-1153Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The manganese(III) complex (2) with a diamide ligand has been synthesized. This complex was found to catalyze both the epoxidation of (Z)- and (E)-stilbene with high conversion and the oxidation of benzyl alcohol to benzaldehyde.

  • 15. Wang, M.
    et al.
    Zhu, H. J.
    Huang, D. G.
    Jin, K.
    Chen, C. N.
    Sun, Licheng C.
    Salen-type zirconium complexes with a labile coordination site and a robust skeleton: crystal structure of (t-Bu-4-salen)ZrCl2(H2O)2004Ingår i: Journal of Organometallic Chemistry, ISSN 0022-328X, E-ISSN 1872-8561, Vol. 689, nr 7, s. 1212-1217Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Treatment of LZrCl2 (L - N, N'-ethylenebis(3,5-di-tert-butylsalicylideneiminato) (1), N, N'-o-phenylenebis(3,5-di-tert-butylsalicylideneiminato) (2)), which is an effective catalyst precursor for ethylene oligomerization, with 1.5 equiv of water in toluene afforded H2O-coordinating salen-type zirconium complexes [LZrCl2(H2O)]. The effects of the content of H2O and the temperature on the equilibrium of association and disassociation of H2O molecule in [LZrCl2(H2O)(n)] (n = 0, 1) were studied in solution (CDCl3) by H-1 NMR spectroscopy. The crystal and molecular structure of [1(H2O)] was determined by X-ray diffraction analysis, which revealed that a herringbone supramolecular assembly was constructed in the crystalline state of [1(H2O)], stacked by the intermolecular hydrogen bonds between the OH group of the coordinating H2O and one of the chloride ligands.

  • 16. Wang, Zhen
    et al.
    Jiang, Wenfeng
    Liu, Jianhui
    Jiang, Weina
    Wang, Yu
    Akermark, Bjoern
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Pendant bases as proton transfer relays in diiron dithiolate complexes inspired by Fe-Fe hydrogenase active site2008Ingår i: Journal of Organometallic Chemistry, ISSN 0022-328X, E-ISSN 1872-8561, Vol. 693, nr 17, s. 2828-2834Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Three dinuclear iron complexes containing pendant nitrogen bases in phosphine ligands with general formular ( l- pdt) [ Fe2( CO) 5L] ( where pdt is SCH2CH2CH2S, L = PPh2NH( CH2) 2N( CH3) 2 ( 5), PPh2NH( 2- NH2C6H4) ( 6), PPh2[ 2- N( CH3) 2CH2C6H4] ( 7)), were prepared as the models of the [ Fe - Fe] hydrogenase active site. The molecular structures of 5 - 7 were characterized by X- ray crystallography. The secondary amine in 6 has weak intramolecular hydrogen bonding with both the terminal nitrogen and sulfur atom, which may suggest a proton transfer pathway from amine in phosphine ligand to the sulfur atom of active site. Protonation of complexes 5 and 6 only occurred at the terminal nitrogen atom. Electrochemical properties of the complexes were studied in the presence of tri. ic acid by cyclic voltammetry.

  • 17. Wang, Zhen
    et al.
    Liu, Jian-Hui
    He, Cheng-Jiang
    Jiang, Shi
    Akermark, Bjorn
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Azadithiolates cofactor of the iron-only hydrogenase and its PR3-monosubstituted derivatives: Synthesis, structure, electrochemistry and protonation2007Ingår i: Journal of Organometallic Chemistry, ISSN 0022-328X, E-ISSN 1872-8561, Vol. 692, nr 24, s. 5501-5507Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The core structure (mu-SCH2)(2)NH[Fe-2(CO)(6)](5) of Fe-only hydrogenases active site model has been synthesized by the condensation of iron carbonyl sulfides, formaldehyde and silyl protected amine. Its monosubstituted complexes (mu-SCH2)(2)NH[Fe-2(CO)(5)PR3] (R = Ph (6), Me (7)) were accordingly prepared. The coordination configurations of 5 and 6 were characterized by X-ray crystallography. Protonation of complex 7 to form the N-protonated product occurs in an acetonitrile solution upon addition of triflic acid. The redox properties of these model complexes were studied by cyclic voltammetry.

  • 18. Zhao, Zhenbo
    et al.
    Wang, Mei
    Dong, Weibing
    Li, Ping
    Yu, Ze
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Synthesis and characterization of carboxy-functionalized diiron model complexes of FeFe -hydrogenases: Decarboxylation of Ph2PCH2COOH promoted by a diiron azadithiolate complex2009Ingår i: Journal of Organometallic Chemistry, ISSN 0022-328X, E-ISSN 1872-8561, Vol. 694, nr 15, s. 2309-2314Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Two carboxy-functionalized diiron complexes [{(mu-SCH2)(2)X}{Fe(CO)(3)}{Fe(CO)(2)L}] (X = NC3H7, L = Ph2PCH2CH2COOH, 4; X = CH2, L = Ph2PCH2COOH, 5) were prepared, as biomimetic models of the [FeFe] hydrogenase active site, from the CO-replacement of [{(mu-SCH2)(2)NC3H7}Fe-2(CO)(6)] (1) and (mu-pdt)Fe-2(CO)(6) (2) by phosphine ligands in CH3CN at 40 degrees C, respectively. In contrast, the reaction of 1 with Ph2PCH2COOH under the same condition afforded complex [{(mu-SCH2)(2)NC3H7}{Fe(CO)(3)}{Fe- (CO)(2)(Ph2PCH3)}] (3) with a decarboxylated phosphine ligand. The molecular structures of complexes 3-5 were determined by X-ray crystallographic analyses, which show that they have similar frameworks with the phosphine ligand on the apical position. The interesting C-H center dot center dot center dot S contacts between the methylene hydrogen atoms of the PhCH2COOH ligand and the mu-S atoms of the pdt-bridge are found in the crystal of 5. According to the experimental evidence, a plausible mechanism, via sequential phosphine coordination, N-protonation, and decarboxylation steps, is proposed for the formation of 3 and for explanation of the contrastive reactivities of the adt- (2-aza-1,3-propanedithiolato) and the pdt-(1,3-propanedithiolato) bridged diiron complexes toward decarboxylation of the Ph2PCH2COOH ligand.

  • 19. Zhu, H. J.
    et al.
    Wang, M.
    Ma, C. B.
    Li, B.
    Chen, C. N.
    Sun, Licheng C.
    Preparation and structures of 6-and 7-coordinate salen-type zirconium complexes and their catalytic properties for oligomerization of ethylene2005Ingår i: Journal of Organometallic Chemistry, ISSN 0022-328X, E-ISSN 1872-8561, Vol. 690, nr 17, s. 3929-3936Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A series of salen-type zirconium complexes of the general formula LZrCl2 (L = N,N '-ethylenebis(salicylideneiminate), 3a; N,N '-ethylenebis(3,5-di-tert -butylsalicylideneiminate), 3b; N,N '-ethylenebis(5-methoxysalicylidenciminate), 3e; N,N '-o-phethylenebis(5-chlorosalicylideneiminate), 3d; N,N '-ethylenebis(5-nitrosalicylideneiminate), 3e; N,N '-o-phenylenebis(salicylideneiminate), 4a; N,N '-o-phenylenebis(3,5-di-tert-butylsalicylideneiminate), 4b; N,N '-o-phenylenebis(5-methoxysalicylideneiminate), 4c; N,N '-o-phenylenebis(5-chloro-salicylideneiminate), 4d) were prepared. The crystal structures of 6- and 7-coordinate zirconium complexes 4b and [4b center dot OCMe2] were determined by X-ray crystallography, which reveals that a salen-type zirconium complex possesses a labile coordination site on the Zr center with a relatively stable framework and that the coordination and the dissociation of O-donor molecules occur readily at this site. The catalytic properties of 3(a-e) and 4(a-d) were studied for ethylene oligomerization in combination with Et2AlCl as co-catalyst. Complex 3c featuring a methoxy-substituted salen ligand displayed higher activity than its analogous precursors having chloro and nitro groups as substituents. The catalytic reactions by 3(a-e) and 4(a-d) gave C-4-C-10 olefins and low-carbon linear (alpha-olefins in good selectivity.

  • 20.
    Åkerstedt, Josefin
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Oorganisk kemi (stängd 20110630).
    Gorlov, Mikhail
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Fischer, Andreas
    KTH, Skolan för kemivetenskap (CHE), Kemi, Oorganisk kemi (stängd 20110630).
    Kloo, Lars
    KTH, Skolan för kemivetenskap (CHE), Kemi, Oorganisk kemi (stängd 20110630).
    Synthesis and characterization of binuclear palladium(I) compounds and the influence of competing arenes2010Ingår i: Journal of Organometallic Chemistry, ISSN 0022-328X, E-ISSN 1872-8561, Vol. 695, nr 10-11, s. 1513-1517Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The binuclear palladium(I) compounds, [Pd-2(Ga2Cl7)(2)(C7H8)(2)] (1), [Pd-2(GaCl4)(2)(C9H12)(2)]center dot C9H12 (2) and [Pd-2(Ga2Cl7)(2)(C6H5Cl)(2)] (3), have been prepared from palladium(II) chloride in gallium(III) chloride-arene reaction media. All isolated crystalline solids (1, 2 and 3) have been structurally characterized by single crystal X-ray diffraction and Raman spectroscopy. The results form quantum chemical calculations on the interaction energies of the arenes and the dipalladium unit of these compounds is also presented.

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