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Conformational analysis of acetamide in the ground and lowest excited electronic states
Journal of Quantitative Spectroscopy and Radiative Transfer. 2017. Vol. 192. P. 30–41.
Тукачев Н. В., Bataev V. А., Godunov I. А.
For acetamide molecule (CH3CONH2) in the ground (S0) and lowest excited singlet (S1) and triplet (T1) electronic states calculations of equilibrium geometry parameters, harmonic vibrational frequencies and barriers to conformational transitions (also conformer energy differences in excited states) using following ab initio methods: MP2, CCSD(T), CASSCF, CASPT2 and MRCI were performed. One-, two- and three-dimensional potential energy surface (PES) sections by different large amplitude motions (LAM) coordinates were calculated by means of MP2/aug-cc-pVTZ (S0) and CASPT2/cc-pVTZ (S1, T1). As a result of electronic excitation, both CCON and CNH2 fragments become pyramidal. On 2D PES sections by torsion (CN) and inversion coordinates there are six minima forming three pairs of enantiomers. Using PES sections different anharmonic vibrational problems were solved and the frequencies of large amplitude vibrations were estimated.
Тукачев Н. В., Bataev V., Abramenkov A. et al., Computational and Theoretical Chemistry 2016 No. 1080 P. 23–32
Electronic state calculations, such as equilibrium geometry parameters, harmonic vibrational frequencies and potential barriers to conformational transitions (as well as conformer energy differences in excited states), using ab initio methods, such as MP2, CCSD(T), CASSCF, CASPT2 and MRCI, were carried out on the formamide molecule in the ground (S0) and the lowest excited singlet (S1) ...
Added: October 14, 2026
Тукачев Н. В., Bataev V. А., Godunov I. А., Journal of Quantitative Spectroscopy and Radiative Transfer 2016 Vol. 177 P. 291–300
For conformers of the N-methylformamide (HCONHCH3) molecule, calculations of equilibrium geometry parameters, harmonic vibration frequencies, energy differences and potential barriers to conformational transitions were performed in the ground (S0) and lowest excited singlet (S1) and triplet (T1) electronic states. In the S0 state, the molecule exists in trans and cis stable conformations (having Cs symmetry). ...
Added: October 14, 2026
Тукачев Н. В., Bataev V. A., Godunov I. A., Computational and Theoretical Chemistry 2017 Vol. 1113 P. 82–93
Equilibrium geometry parameters, harmonic vibrational frequencies and barriers to conformational transitions and conformer energy differences for N-methylacetamide (CH3CONHCH3) molecule in S0, S1 and T1 electronic states were calculated in MP2 (S0) and CASPT2 (S1, T1) levels of theory. It is known that there are two planar (or effectively planar) conformers of N-methylacetamide in the ground ...
Added: October 14, 2026
Тукачев Н. В., Maslennikov D., Sosorev A. et al., The Journal of Physical Chemistry Letters 2019 Vol. 10 No. 12 P. 3232–3239
Conformational space of polyphenylenevinylene oligomers is systematically investigated computationally at energies relevant for room temperature dynamics in a solvent and in a solid state. Our calculations show that optimal oligomer structures are essentially planar. However, lack of a deep minimum at the planar geometry allows for large molecular deformations even at very low temperatures. At ...
Added: October 14, 2026
Тукачев Н. В., Akkuratov A., Kuznetsov I. et al., Synthetic Metals 2020 Vol. 259 Article 116231
Four new conjugated polymers based on benzodithiophene, thiophene and 2,1,3-benzothiadiazole or 5,6-difluoro-2,1,3-benzothiadiazole were synthesized and investigated as absorber materials for organic photovoltaics. The effect of (bi)thiophene π-spacers and fluorine substitution on the physicochemical and optoelectronic properties of the polymers was revealed and correlations were drawn with their electrical characteristics in organic solar cells. In particular, ...
Added: October 14, 2026
Тукачев Н. В., Nuraliev M., Parashchuk O. et al., Journal of Chemical Physics 2020 Vol. 153 No. 17 Article 174303
Electron–phonon interaction strongly affects and often limits charge transport in organic semiconductors (OSs). However, approaches to its experimental probing are still in their infancy. In this study, we probe the local electron–phonon interaction (quantified by the charge-transfer reorganization energy) in small-molecule OSs by means of Raman spectroscopy. Applying density functional theory calculations to four series ...
Added: October 14, 2026
Тукачев Н. В., Akkuratov A., Nikitenko S. et al., Solar Energy 2020 Vol. 198 P. 605–611
One of the major challenges in the field of organic photovoltaics is associated with high-throughput manufacturing of efficient and stable organic solar cells. Practical realization of technologies for production of large-area organic solar cells requires the development of novel materials with a defined combination of properties ensuring sufficient reliability and scalability of the process in ...
Added: October 14, 2026
Тукачев Н. В., Klimovich I., Prudnov F. et al., Dyes and Pigments 2021 Vol. 185 Article 108899
A series of ten conjugated polymers incorporating in their molecular frameworks extended DADAD building blocks with thiophene donor (D) and either benzotriazole, benzoxadiazole, benzothiadiazole, difluorobenzothiadiazole or quinoxaline acceptor (A) units were synthesized and characterized. The optoelectronic properties of new polymers were computed and experimentally investigated revealing a good relationship, which can guide further rational design ...
Added: October 14, 2026
Тукачев Н. В., Sosorev A., Parashchuk O. et al., Physical Chemistry Chemical Physics 2021 Vol. 23 No. 29 P. 15485–15491
Dynamic disorder manifested in fluctuations of charge transfer integrals considerably hinders charge transport in high-mobility organic semiconductors. Accordingly, strategies for suppression of the dynamic disorder are highly desirable. In this study, we suggest a novel promising strategy for suppression of dynamic disorder—tuning the molecular electrostatic potential. Specifically, we show that the intensities of the low-frequency ...
Added: October 14, 2026
Тукачев Н. В., González-Jiménez M., Ramakrishnan G. et al., Physical Chemistry Chemical Physics 2021 Vol. 23 No. 23 P. 13250–13260
Low-frequency vibrations play an essential role in biomolecular processes involving DNA such as gene expression, charge transfer, drug intercalation, and DNA–protein recognition. However, understanding the vibrational basis of these mechanisms relies on theoretical models due to the lack of experimental evidence. Here we present the low-frequency vibrational spectra of G-quadruplexes (structures formed by four strands ...
Added: October 14, 2026
Тукачев Н. В., González-Jiménez M., Barnard T. et al., Nature Communications 2023 Vol. 14 Article 215
A common feature of glasses is the “boson peak”, observed as an excess in the heat capacity over the crystal or as an additional peak in the terahertz vibrational spectrum. The microscopic origins of this peak are not well understood; the emergence of locally ordered structures has been put forward as a possible candidate. Here, ...
Added: October 14, 2026
Тукачев Н. В., Mali G., Tassieri M. et al., Journal of the American Chemical Society, USA 2023 Vol. 145 No. 48 P. 26061–26067
On supercooling a liquid, the viscosity rises rapidly until at the glass transition it vitrifies into an amorphous solid accompanied by a steep drop in the heat capacity. Therefore, a pure homogeneous liquid is not expected to display more than one glass transition. Here we show that a family of single-component homogeneous molecular liquids, titanium ...
Added: October 14, 2026
Тукачев Н. В., Dubinets N. O., Dominskiy D. I. et al., Optical Materials 2024 Vol. 157 No. 2 P. 1–8
Donor-acceptor molecules exhibiting TADF are in the heart of third-generation OLEDs. In this study, we apply (TD)DFT and multiscale modelling to assess the reliability of these approaches for prediction of the emission properties of carbazole-triazine (Cz-TRZ) based TADF luminophores. We found that a series of hybrid and doubly hybrid functionals reproduce the experimentally observed trend ...
Added: October 14, 2026