Evgeny A. Mostovich

Bio: Evgeny A. Mostovich is an academic researcher from Novosibirsk State University. The author has contributed to research in topics: Phenylene & Luminescence. The author has an hindex of 9, co-authored 22 publications receiving 180 citations. Previous affiliations of Evgeny A. Mostovich include Russian Academy of Sciences & Max Planck Society.

Way to Highly Emissive Materials: Increase of Rigidity by Introduction of a Furan Moiety in Co-Oligomers

Abstract: Rigid linear organic co-oligomers are prospective materials for organic optoelectronics In this work, we explored intramolecular factors affecting the torsional rigidity and its influence on optoelectronic properties of the alternating furan/phenylene and thiophene/phenylene co-oligomers in both ground and first singlet excited states Furan/phenylene co-oligomer exhibits almost twice higher torsional rigidity than its thiophene analog Effect of intramolecular O…H and S…H interactions on torsional barriers was found to be negligible as compared with the conjugation efficiency The higher torsional rigidity of furan and thiophene co-oligomers has been proven to be reflected in the fine-structure of the UV-Vis absorption spectrum of the former The increase of furan co-oligomer rigidity as compared with its thiophene analog lowers reorganization energy for hole, electron and exciton transfer Remarkably the substitution of thiophene by furan almost 20 times lowers reorganization energy for exciton transfe

Highly-emissive solution-grown furan/phenylene co-oligomer single crystals

Abstract: Solution-processed furan/phenylene co-oligomer single crystals combine high photoluminescence quantum yield (>65%) and efficient charge transport (mobility 0.12 cm2 V−1 s−1) making them promising materials for printable organic optoelectronics.

Methyl substituent effect on structure, luminescence and semiconducting properties of furan/phenylene co-oligomer single crystals

Abstract: Single crystals of furan/phenylene co-oligomers are among the most promising highly-emissive materials for applications in various optoelectronic devices. In this work, we synthesized and studied furan/phenylene co-oligomers with the same conjugated core 1,4-bis(5-phenylfuran-2-yl)benzene and methyl substituents at p- and m-positions of the terminal phenyls. The effect of substituents on the crystal packing, charge transport and luminescence of the single crystals was studied. Compared to the unsubstituted compound, the methyl-substituted co-oligomers demonstrated improved thermostability and enhanced photoluminescence, which we assign to J-aggregation resulting from the strong inclination of the molecules against the main crystal facet. The charge mobility in single crystal organic field-effect transistors decreased upon the inclination of the molecules. We conclude that the molecular tilt angle, intermolecular distances and interactions in crystals of heteroaryl-containing linear conjugated oligomers can be controlled by the introduction of end methyl groups in the appropriate positions.

Planar Biphenyl-Bridged Biradicals as Building Blocks for the Design of Quantum Magnets

Abstract: We have synthesized and investigated a new biphenyl-4,4′-bis(nitronyl nitroxide) radical with intermediately strong antiferromagnetic interactions. This organic biradical belongs to a family of materials that can be used as a building block for the design of new quantum magnets. For quantum magnetism, special attention has been paid to coupled S = 1/2 dimer compounds, which when placed in a magnetic field, can be used as model systems for interacting boson gases. Short contacts between the oxygen atoms of the nitronyl nitroxide units and the hydrogen atoms of the benzene rings stabilize a surprisingly planar geometry of the biphenyl spacer and are responsible for a small magnetic interdimer coupling. The strength of the antiferromagnetic intradimer coupling constant J/kB = −14.0 ± 0.9 K, fitting the experimental SQUID-data using an isolated-dimer model. The deviations from the isolated-dimer model are attributed to a small interdimer coupling J′/kB, on the order of 1 K, consistent with the crystal structure.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

Recent Advances in Organic Radicals and Their Magnetism

Abstract: The review presents an overview of the organic radicals that have been designed and synthesized recently, and their magnetic properties are discussed. The π-conjugated organic radicals such as phenalenyl systems, functionalized nitronylnitroxides, benzotriazinyl, bisthiazolyl, aminyl-based radicals and polyradicals, and Tetrathiafulvalene (TTF)-based H-bonded radicals have been considered. The examples show that weak supramolecular interactions play a major role in modulating the ferromagnetic and antiferromagnetic properties. The new emerging direction of zethrenes, organic polyradicals, and macrocyclic polyradicals with their attractive and discrete architectures has been deliberated. The magnetic studies delineate the singlet-triplet transitions and their corresponding energies in these organic radicals. We have also made an attempt to collate the major organic neutral radicals, radical ions and radical zwitterions that have emerged over the last century.