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Biler, Michal
Publications (4 of 4) Show all publications
Linares, M., Sun, H., Biler, M., Andreasson, J. & Norman, P. (2019). Elucidating DNA binding of dithienylethenes from molecular dynamics and dichroism spectra. Physical Chemistry, Chemical Physics - PCCP, 21(7), 3637-3643
Open this publication in new window or tab >>Elucidating DNA binding of dithienylethenes from molecular dynamics and dichroism spectra
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2019 (English)In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 21, no 7, p. 3637-3643Article in journal (Refereed) Published
Abstract [en]

DNA binding modes of the stereoisomeric rotamers of two dithenylethene derivatives (DTE1 and DTE2) representing candidate molecular photoswitches of great promise for photopharmacology and nanotechnology have been identified and characterized in terms of their binding energies and electronic circular dichroism (CD) responses. In the open form, two binding modes are identified namely minor-groove binding of the lowest-energy conformer with an anti-parallel arrangement of methyl groups and major-groove double-intercalation of the P-enantiomers of an intermediate-state rotamer. Only the latter binding mode is found to be enantiomerically selective and expected to have an overall negative linear dichroism (LD) as observed in the experiment for DTE1 (Angew. Chem., Int. Ed., 2013, 52, 4393). In the closed form, the most favorable binding mode is found to be minor groove binding. Also this binding mode is found to be enantiomerically selective and for DTE1, it is the M-enantiomer that binds the strongest, showing a positive theoretical signature CD band in the long wavelength region with origin in pyridinium ligands. The theoretical CD spectrum is found to be in good agreement with the experimental one, which provides an indirect evidence for a correct identification of the binding mode in the closed form.

Place, publisher, year, edition, pages
ROYAL SOC CHEMISTRY, 2019
National Category
Physical Chemistry
Identifiers
urn:nbn:se:kth:diva-246264 (URN)10.1039/c8cp05326j (DOI)000459585900024 ()30379159 (PubMedID)2-s2.0-85061512565 (Scopus ID)
Note

QC 20190326

Available from: 2019-03-26 Created: 2019-03-26 Last updated: 2019-03-26Bibliographically approved
Cornelissen, T. D., Biler, M., Urbanaviciute, I., Norman, P., Linares, M. & Kemerink, M. (2019). Kinetic Monte Carlo simulations of organic ferroelectrics. Physical Chemistry, Chemical Physics - PCCP, 21(3), 1375-1383
Open this publication in new window or tab >>Kinetic Monte Carlo simulations of organic ferroelectrics
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2019 (English)In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 21, no 3, p. 1375-1383Article in journal (Refereed) Published
Abstract [en]

Ferroelectrics find broad applications, e.g. in non-volatile memories, but the switching kinetics in real, disordered, materials is still incompletely understood. Here, we develop an electrostatic model to study ferroelectric switching using 3D Monte Carlo simulations. We apply this model to the prototypical small molecular ferroelectric trialkylbenzene-1,3,5-tricarboxamide (BTA) and find good agreement between the Monte Carlo simulations, experiments, and molecular dynamics studies. Since the model lacks any explicit steric effects, we conclude that these are of minor importance. While the material is shown to have a frustrated antiferroelectric ground state, it behaves as a normal ferroelectric under practical conditions due to the large energy barrier for switching that prevents the material from reaching its ground state after poling. We find that field-driven polarization reversal and spontaneous depolarization have orders of magnitude different switching kinetics. For the former, which determines the coercive field and is relevant for data writing, nucleation occurs at the electrodes, whereas for the latter, which governs data retention, nucleation occurs at disorder-induced defects. As a result, by reducing the disorder in the system, the polarization retention time can be increased dramatically while the coercive field remains unchanged.

Place, publisher, year, edition, pages
ROYAL SOC CHEMISTRY, 2019
National Category
Theoretical Chemistry
Identifiers
urn:nbn:se:kth:diva-243951 (URN)10.1039/c8cp06716c (DOI)000456147000040 ()30601493 (PubMedID)2-s2.0-85060120855 (Scopus ID)
Note

QC 20190304

Available from: 2019-03-04 Created: 2019-03-04 Last updated: 2019-03-12Bibliographically approved
Urbanaviciute, I., Bhattacharjee, S., Biler, M., Lugger, J. A. M., Cornelissen, T. D., Norman, P., . . . Kemerink, M. (2019). Suppressing depolarization by tail substitution in an organic supramolecular ferroelectric. Physical Chemistry, Chemical Physics - PCCP, 21(4), 2069-2079
Open this publication in new window or tab >>Suppressing depolarization by tail substitution in an organic supramolecular ferroelectric
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2019 (English)In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 21, no 4, p. 2069-2079Article in journal (Refereed) Published
Abstract [en]

Despite being very well established in the field of electro-optics, ferroelectric liquid crystals so far lacked interest from a ferroelectric device perspective due to a typically high operating temperature, a modest remnant polarization and/or poor polarization retention. Here, we experimentally demonstrate how simple structural modification of a prototypical ferroelectric liquid-crystal benzene-1,3,5-trisamide (BTA) - introduction of branched-tail substituents - results in materials with a wide operating temperature range and a data retention time of more than 10 years in thin-film solution-processed capacitor devices at room temperature. The observed differences between linear- and branched-tail compounds are analyzed using density functional theory (DFT) and molecular dynamics (MD) simulations. We conclude that morphological factors like improved packing quality and reduced disorder, rather than electrostatic interactions or intra/inter-columnar steric hindrance, underlay the superior properties of the branched-tailed BTAs. Synergistic effects upon blending of compounds with branched and linear side-chains can be used to further improve the materials' characteristics.

Place, publisher, year, edition, pages
ROYAL SOC CHEMISTRY, 2019
National Category
Physical Chemistry
Identifiers
urn:nbn:se:kth:diva-246286 (URN)10.1039/c8cp06315j (DOI)000459584100039 ()30638230 (PubMedID)2-s2.0-85060382616 (Scopus ID)
Note

QC 20190325

Available from: 2019-03-25 Created: 2019-03-25 Last updated: 2019-03-25Bibliographically approved
Biler, M., Biedermann, D., Valentova, K., Kren, V. & Kubala, M. (2017). Quercetin and its analogues: optical and acido-basic properties. Physical Chemistry, Chemical Physics - PCCP, 19(39), 26870-26879
Open this publication in new window or tab >>Quercetin and its analogues: optical and acido-basic properties
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2017 (English)In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 19, no 39, p. 26870-26879Article in journal (Refereed) Published
Abstract [en]

This study is focused on eight structurally analogous natural flavonoids that exhibit a wide range of biological activities, which are of interest in pharmacy, cosmetics and the food industry. Using both experimental and theoretical approaches, we relate their fundamental physico-chemical properties to the structural motifs, with particular focus on UV/Vis absorption properties and pH dependence. We highlight the role of the C2-C3 double bond, whose presence or absence is responsible for the switch between absorption bands in the UVB and UVA regions, which is rationalized by strong modification of the involved molecular orbitals. After deprotonation in an alkaline environment, a typical switch in intensity at the maximum absorption wavelength (lambda(max)) is observed enabling the calculation of pK(a) values for compounds with a C2-C3 single bond, whereas a bathochromic shift of lambda(max) vs. pH is observed for the C2-C3 double bond containing compounds. These behaviors are also rationalized and understood by MO analysis. Interestingly, high pH (above 11 for ampelopsin and above 9 for myricetin) induces the formation of a long-wavelength peak arising from double and/or triple deprotonation. Substitution at position C3 by the OH group has almost no effect on lambda(max) for taxifolin and eriodictyol, whereas the effect is larger for quercetin and luteolin. An additional sugar moiety at C3 has a stabilizing effect and induces only minor changes in spectral behavior.

Place, publisher, year, edition, pages
ROYAL SOC CHEMISTRY, 2017
National Category
Other Chemistry Topics
Identifiers
urn:nbn:se:kth:diva-217032 (URN)10.1039/c7cp03845c (DOI)000412763700041 ()28952614 (PubMedID)2-s2.0-85031317204 (Scopus ID)
Note

QC 20171124

Available from: 2017-11-24 Created: 2017-11-24 Last updated: 2017-11-24Bibliographically approved
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