Churakov, Andrei V

Tatarin S.V., Krasnov L., Nykhrikova E.V., Minin M.M., Smirnov D.E., Churakov A.V., Bezzubov S.

Cyclometalated iridium(III) complexes are excellent emitters for organic light-emitting diodes (OLEDs), but the design of these compounds requires substantial cost and experimental efforts. In this work, we aimed at a...

Medvedev A.G., Prikhodchenko P.V., Dalinger I.L., Vener M.V., Churakov A.V.

Medvedev A.G., Mel'nik E.A., Mikhaylov A.A., Mayorov N.S., Tripol'skaya T.A., Lev O., Prikhodchenko P.V., Churakov A.V.

scXRD and solid-sate DFT studies of hydrogen bonding of H2O2 molecules in adducts with alkali metal and tetraethylammonium nitrates.

Anokhin D.V., Plieva D.S., Rosenthal M., Churakov A.V., Ivanov D.A.

Synchrotron microbeam X-ray diffraction was employed to investigate the local-scale structure and solid-state phase transformation within individual spherulites of poly(vinylidene fluoride) (PVDF). In thin, non-oriented films, PVDF crystallizes into α and γ-phases, forming distinct spherulitic morphologies: large, banded α-spherulites and smaller, irregular “mixed” spherulites dominated by the γ-phase. For samples crystallized at high undercooling (160 °C), the mixed spherulites primarily consisted of the γ-phase, with only a minor fraction of α-lamellae localized at the spherulite boundaries. At higher crystallization temperatures (165 °C), the α-phase was entirely absent from the mixed spherulites. High-temperature annealing induced a phase transformation from the α-phase to the γ-phase, initiating at the interface between α- and γ-spherulites. The transformation propagated radially along the b-axis of the α-spherulite, while its characteristic banded morphology remained intact. Radial scanning with an X-ray microbeam provided spatially resolved mapping of the structural transition within the α-spherulite at the micrometer scale, offering detailed insights into the transformation mechanism and its impact on the spherulitic structure. The fast crystal growth direction remained unaltered during the transition, suggesting minimal material transport and maintaining structural coherence.

Kalle P., Bezzubov S.I., Latipov E.V., Churakov A.V.

Simonov A.Y., Panov A., Churakov A.V., Polshakov V.I., Levshin I.B.

AbstractThe reaction of thiazolidine‐2,4‐diones (TZDs) with oxiranes has been thoroughly investigated. For the first time, it has been observed that 5‐arylidene‐TZD derivatives can undergo transformation into 6‐substituted 1,4‐oxathian‐2‐ones. Additionally, it has been demonstrated that certain 3‐substituted 5‐arylidene‐TZDs can convert to 1,4‐oxathian‐2‐ones and oxazolidines upon reaction with oxiranes, confirming that the process follows a cascade mechanism. Several factors have been found to influence the reaction‘s outcome, including the amount of oxirane, the presence of a base, and solvent polarity. It has been determined that dimethylformamide (DMF) is essential for the reaction to proceed efficiently. Furthermore, the critical role of the benzylidene group in facilitating the reaction has been confirmed. An unusual hydrogen bond between the ortho‐hydrogens of the phenyl group and the sulfur atom of the thiazolidine ring, observed via NMR spectroscopy, highlights the sulfur atom‘s strong electron‐accepting properties, which play a key role in the observed transformations.

Anokhin D.V., Plieva D.S., Rosenthal M., Churakov A.V., Ivanov D.A.

Synchrotron microbeam X-ray diffraction was employed to investigate the local-scale structure and solid-state phase transformation within individual spherulites of poly(vinylidene fluoride) (PVDF). In thin, non-oriented films, PVDF crystallizes into α and γ phases, forming distinct spherulitic morphologies: large, banded α-spherulites and smaller, irregular “mixed” spherulites dominated by the γ-phase. For samples crystallized at high undercooling (160 °C), the mixed spherulites primarily consisted of the γ-phase, with only a minor fraction of α-lamellae localized at the spherulite boundaries. At higher crystallization temperatures (165 °C), the α-phase was entirely absent from the mixed spherulites. High-temperature annealing induced a phase transformation from the α-phase to the γ-phase, initiating at the interface between α- and γ-spherulites. The transformation propagated radially along the b-axis of the α-spherulite, while its characteristic banded morphology remained intact. Radial scanning with an X-ray microbeam provided spatially resolved mapping of the structural transition within the α-spherulite at the micrometer scale, offering detailed insights into the transformation mechanism and its impact on the spherulitic structure. The fast crystal growth direction remained unaltered during the transition, suggesting minimal material transport and maintaining structural coherence.

Churakov A.V., Anokhin D.V., Kalle P., Kiseleva M.A., Vener M.V., Kuz’mina L.G.

Three novel solvatomorphs (C13H29NO3S•CH3OH, 1; C13H29NO3S•0.113(H2O), 2; C13H29NO3S•0.038(H2O), 3) of zwitterionic sulfobetaine-8 were obtained and their structures were determined using single-crystal X-Ray diffraction. In all cases dimethyl–amino substituted hydrophobic chains -(CH2)3-N+Me2-(CH2)7-Me exhibit kinks at nitrogen atoms resulted from strong intra- and intermolecular CH⋯O hydrogen bonds between negatively charged sulfonic anion -O3S- and positively charged tetraalkylammonium fragments. Periodic (solid state) DFT calculations for structure 1 showed that the energy of the intermolecular hydrogen bonds CH…O is very high, at about 17 kJ/mol. In hydrates 2 and 3, water molecules play the structure-forming role since they interconnect hydrophobic layers by HOH…-O3S hydrogen bonds. The location of only partially occupied water molecules in the interlayer space leads to low stability of both crystals 2 and 3 in open air.

Churakov A.V., Medvedev A.G., Frolov N.E., Vener M.V.

Three novel multicomponent crystals of trimethylglycine with 2-cyanoguanidine, guanidinium and aminoguanidinium chlorides are synthesized and structurally characterized. All three crystal packings are based on the supramolecular synthon formed by two N–H groups of the guanidine species and carboxylate group of trimethylglycine (graph set notation R22(8)). Its enthalpy is about 50 kJ/mol. The three-dimensional structure of crystals is stabilized by intermolecular interactions of various types. The energy of C–H∙∙∙X− interactions, where X = O, Cl, reaches 16 kJ/mol due to the acidic nature of methyl hydrogens. The possible structure of the trimethylglycine–urea–2H2O complex is discussed. Its theoretical metric and spectroscopic parameters are in reasonable agreement with the available literature data on the deep eutectic solvent trimethylglycine–urea.

Tatarin S., Krasnov L., Nykhrikova E., Minin M., Smirnov D., Churakov A., Bezzubov S.

Cyclometalated iridium(III) complexes are excellent emitters for phosphorescent organic light-emitting diodes, but the design of such complexes require substantial cost and experimental efforts. In turn, the predictive power of density functional theory calculations is seldom enough for reliable prediction of the excited state properties of iridium(III) complexes. In this work, we aimed at data-driven prediction of the emission energies and photoluminescence quantum yields of such complexes. To this end, we created a database (IrLumDB) that contains experimentally measured luminescence properties for over 1200 literature bis-cyclometalated iridium(III) complexes. Based on this database, we developed machine learning models that are capable of predicting the energy of emission maxima and photoluminescence quantum yields for the iridium phosphors with mean absolute errors of 18.26 nm and 0.129, respectively, requiring only SMILES of ligands. Furthermore, we validated the model for emission wavelength prediction on the set of 33 experimentally obtained luminescence spectra for newly synthesized and characterized iridium(III) complexes. Our data-driven methodology will complement quantum chemical calculations as an efficient alternative approach for the prediction of the excited-state properties of large sets of bis-cyclometalated iridium(III) complexes, facilitating computational discovery of efficient emitters. The emission properties prediction and the dataset exploration are available at https://irlumdb.streamlit.app/.

Voronin A.P., Ramazanova A.G., Churakov A.V., Vologzhanina A.V., Kulikova E.S., Perlovich G.L.

Kalle P., Bezzubov S.I., Kuzmina L.G., Churakov A.V.

Andrei C.

Crystallization of antimicrobial compound furacin (nitrofurazone) from 96%, 50%, and 20% hydrogen peroxide (HP) led to three novel solvates C6H6N4O4•H2O2, C6H6N4O4•1.5(H2O2), and C6H6N4O4•3.5(H2O2), respectively. Surprisingly, more rich in hydrogen peroxide...

Il'in E., Parshakov A., Churakov A., Iskhakova L., Filippova A., Kottsov S., Demina L., Goeva L., Simonenko N., Privalov V., Baranchikov A., Ivanov V.

Fedulin A.I., Oprunenko Y.F., Egorov A.R., Churakov A.V., Zaitsev K.V.

Zhao Q., Zhang J., Jing Y., Xue J., Liu J., Qin J., Hong Z., Du Y.

Couturier J., Levard C., Collin B., Chaurand P., Vidal V., Mathon O., Duvivier A., Angeletti B., Borschneck D., Rose J., Pellet-Rostaing S., Arrachart G.

Tokárová Z., Kabaňová N., Korcová J., Gallová L., Tokár K., Végh D.

Dedov A.G., Loktev A.S., Stolyarov I.P., Maslakov K.I., Bykov M.A., Sadovnikov A.A., Cherednichenko K.A., Shandryuk G.A.

Malik M., Mazur T., Crans D.C., Komarnicka U.K.

Luo P., Zeng J., Lu F., Zhong G.

Peng H., Guo Y., Ma G., Fan X., Shu K., Li Y., Liao J., Liu N., Li F., Ma L.

Yan T., Li H., Xi D., Sun L., Liu L., Jin D.

Musa A.F., Elsenety M.M., Faraghally F.A., Kumar A., Chu C., Wei T.

Freitas J.T., Martins L.D., Magalhães Calisto V.F., Beraldo H., Diniz R.

Nikolaevskaya E.N., Syroeshkin M.A., Egorov M.P., Karlov S.S.

Hou L., Zhang M., Shi L., Luo X., De R., Chen W., Jing Y., Bao Y.

Hamzehlou S., Rahimpour E., Fathi Azarbayjani A., Jouyban A.

Volkova T.V., Simonova O.R., Perlovich G.L.

Al Ahmad A.R., Maris T., Wuest J.D.

Chang Q., Zhang K., Yan C., Xie L., Yi Y., Su W., Liu W.

Organic light-emitting diodes (OLEDs) based on phosphorescent materials are among the most promising technologies for displays and lightings. For red-emitting heteroleptic iridium complexes (HICs), vast and major research has been focused on the design and synthesis of cyclometalated ligands, while relatively little attention has been given to ancillary ligands which also play important roles in manipulating the optoelectronic and electroluminescent properties of HICs. Seven deep red-emitting HICs were designed and synthesized by systematically modifying the alkyl groups in β-diketone-type ancillary ligands. These HICs exhibited similar physical and optoelectronic properties, with OLED devices based on these materials achieving consistent emission peaks at 624 nm and CIE coordinates of (0.68, 0.32). Among the synthesized HICs, Ir(dmippiq)₂(dmeacac), featuring 3,7-dimethyl-4,6-nonanedione as the ancillary ligand, demonstrated the best OLED performance, achieving a champion external quantum efficiency (EQE) of 18.26%. This result highlights that engineering the alkyl groups in β-diketone ancillary ligands can significantly enhance device performance.

Wang S., Yam C.Y., Hu L., Hung F., Chen S., Che C., Chen G.

The multi-level Δ-learning method significantly advances kr prediction by bridging TDDFT results with experimental values. This approach improves prediction reliability, making it essential for accurate material evaluation.

Churakov A.V., Medvedev A.G., Frolov N.E., Vener M.V.

Three novel multicomponent crystals of trimethylglycine with 2-cyanoguanidine, guanidinium and aminoguanidinium chlorides are synthesized and structurally characterized. All three crystal packings are based on the supramolecular synthon formed by two N–H groups of the guanidine species and carboxylate group of trimethylglycine (graph set notation R22(8)). Its enthalpy is about 50 kJ/mol. The three-dimensional structure of crystals is stabilized by intermolecular interactions of various types. The energy of C–H∙∙∙X− interactions, where X = O, Cl, reaches 16 kJ/mol due to the acidic nature of methyl hydrogens. The possible structure of the trimethylglycine–urea–2H2O complex is discussed. Its theoretical metric and spectroscopic parameters are in reasonable agreement with the available literature data on the deep eutectic solvent trimethylglycine–urea.

Voronin A.P., Ramazanova A.G., Churakov A.V., Vologzhanina A.V., Kulikova E.S., Perlovich G.L.

Kalle P., Bezzubov S.I., Kuzmina L.G., Churakov A.V.

Choroba K., Palion-Gazda J., Penkala M., Rawicka P., Machura B.

The impact of cyclometalating ligands on the photophysical behaviour of heteroleptic Ir(iii) complexes with imidazo[4,5-f][1,10]phenanthroline. [Ir(ppy)2(imphen)]+ is a 3MLLCT emitter, while [Ir(pybzth)2(imphen)]+ has a predominant 3LCN∩C character.

Golubkov S.S., Melnikov A.P., Statsenko T.G., Sanginov E.A., Belmesov A.A., Don G.M., Likhomanov V.S., Kireynov A.V., Kashin A.M., Maryasevskaya A.V., Levchenko A.V., Moutsios I., Ivanov D.A., Morozova S.M.

Tsering D., Dey P., Kapoor K.K., Seth S.K.

Krasnov L., Tatarin S., Smirnov D., Bezzubov S.

AbstractIridium(III) complexes nowadays became rising stars in various health-related applications. Thus, there is a necessity to assess cytotoxicity of the synthesized molecules against cancer/normal cell lines. In this report, we present a dataset of 2694 experimental cytotoxicity values of 803 iridium complexes against 127 different cell lines. We specify the experimental conditions and provide representation of the complexes molecules in machine-readable format. The dataset provides a starting point for exploration of new iridium-based cellular probes and opens new possibilities for predictions of toxicities and data-driven generation of new organometallic anticancer agents.

A. P. V., O. R. S., T. V. V., G. L. P.

The saturated vapour pressures of five heterocyclic compounds containing the pyridine fragment, namely, three isomers of aminopyridine, 3-hydroxypyridine and 2-(1H-imidazol-2-yl)pyridine, were measured using a transpiration method.

Sobornova V.V., Belov K.V., Krestyaninov M.A., Khodov I.A.

The study presents a thorough and detailed analysis of bicalutamide’s structural and conformational properties. Quantum chemical calculations were employed to explore the conformational properties of the molecule, identifying significant energy differences between conformers. Analysis revealed that hydrogen bonds stabilise the conformers, with notable variations in torsion angles. Conformers were classified into ‘closed’ and ‘open’ types based on the relative orientation of the cyclic fragments. NOE spectroscopy in different solvents (CDCl3 and DMSO-d6) was used to study the conformational preferences of the molecule. NOESY experiments provided the predominance of ‘closed’ conformers in non-polar solvents and a significant presence of ‘open’ conformers in polar solvents. The proportions of open conformers were 22.7 ± 3.7% in CDCl3 and 59.8 ± 6.2% in DMSO-d6, while closed conformers accounted for 77.3 ± 3.7% and 40.2 ± 6.2%, respectively. This comprehensive study underscores the solvent environment’s impact on its structural behaviour. The findings significantly contribute to a deeper understanding of conformational dynamics, stimulating further exploration in drug development.

Purushothaman S.M., Tronco M.F., Ponçot M., C.S C., Guigo N., Malfois M., Kalarikkal N., Thomas S., Royaud I., Rouxel D.

Medvedev A.G., Egorov P.A., Mikhaylov A.A., Belyaev E.S., Kirakosyan G.A., Gorbunova Y.G., Filippov O.A., Belkova N.V., Shubina E.S., Brekhovskikh M.N., Kirsanova A.A., Babak M.V., Lev O., Prikhodchenko P.V.

AbstractDespite the significance of H2O2-metal adducts in catalysis, materials science and biotechnology, the nature of the interactions between H2O2 and metal cations remains elusive and debatable. This is primarily due to the extremely weak coordinating ability of H2O2, which poses challenges in characterizing and understanding the specific nature of these interactions. Herein, we present an approach to obtain H2O2–metal complexes that employs neat H2O2 as both solvent and ligand. SnCl4 effectively binds H2O2, forming a SnCl4(H2O2)2 complex, as confirmed by 119Sn and 17O NMR spectroscopy. Crystalline adducts, SnCl4(H2O2)2·H2O2·18-crown-6 and 2[SnCl4(H2O2)(H2O)]·18-crown-6, are isolated and characterized by X-ray diffraction, providing the complete characterization of the hydrogen bonding of H2O2 ligands including geometric parameters and energy values. DFT analysis reveals the synergy between a coordinative bond of H2O2 with metal cation and its hydrogen bonding with a second coordination sphere. This synergism of primary and secondary interactions might be a key to understanding H2O2 reactivity in biological systems.

Pal Y., Fiala T.A., Swords W.B., Yoon T.P., Schmidt J.

AbstractWe report a deep learning‐based approach to accurately predict the emission spectra of phosphorescent heteroleptic [Ir( )2( )]+ complexes, enabling the rapid discovery of novel Ir(III) chromophores for diverse applications including organic light‐emitting diodes and solar fuel cells. The deep learning models utilize graph neural networks and other chemical features in architectures that reflect the inherent structure of the heteroleptic complexes, composed of and ligands, and are thus geared towards efficient training over the dataset. By leveraging experimental emission data, our models reliably predict the full emission spectra of these complexes across various emission profiles, surpassing the accuracy of conventional DFT and correlated wavefunction methods, while simultaneously achieving robustness to the presence of imperfect (noisy, low‐quality) training spectra. We showcase the potential applications for these and related models for in silico prediction of complexes with tailored emission properties, as well as in “design of experiment” contexts to reduce the synthetic burden of high‐throughput screening. In the latter case, we demonstrate that the models allow us to exploit a limited amount of experimental data to explore a wide range of chemical space, thus leveraging a modest synthetic effort.

Ouyang J., Liu L., Li Y., Chen M., Zhou L., Liu Z., Xu L., Shehzad H.

Carbamazepine (CBZ) is an anticonvulsant with very low water solubility, presenting as a white crystalline powder with poor mechanical properties and is hard to bend. To enhance CBZ’s physicochemical properties, such as water solubility and mechanical properties, we selected six cocrystal coformers (CCFs): nicotinamide (NIC), benzamide (BZM), salicylic acid (SCA), fumaric acid (FMA), trimesic acid (TMA) and hesperetin (HPE). Six CBZ cocrystals were successfully prepared using the solution method. Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC) and single crystal X-ray diffraction (SCXRD), were used to characterize the crystal structures and gain comprehensive insights into the six cocrystals. The mechanical, fluorescence and solubility properties of the six cocrystals were tested. The results reveal that most of the prepared cocrystals exhibit improved water solubility and mechanical properties when compared to CBZ. Among them, the dissolution rate of cocrystals excluded CBZ-HPE has increased by an average of 3 or 4 times compared to CBZ, while CBZ-HPE exhibit superior mechanical properties. Moreover, all the six cocrystals possess better fluorescence performance than CBZ. We thoroughly evaluated the mechanical properties of the cocrystals through both experimental and theoretical approaches. This work provides a new direction for studying drug cocrystals to improve the physicochemical properties of drugs.