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Information × Registration Number 0221U103502, 0117U003908 , R & D reports Title Molecular design of materials for organic light-emitting diodes with alternative mechanisms of electroluminescence popup.stage_title Head Baryshnikov Hlib V, Registration Date 21-02-2021 Organization Bohdan Khmelnytsky National University of Cherkasy popup.description2 Main results: 1. The structure of the molecules of hetero[n]circulenes can be characterized based on the strain energy of the macrocycle as the main descriptor for assessing the stability of their molecules. It was established that the increase in the macrocycle size (n = 10–30) for higher heterocirculenes leads to a gradual transformation of their structure from saddle-shaped to spiral, and then to wing-shaped structure. At the same time, the lower representatives with n = 4, 6 show a bowl-shaped structure due to the high strain energy of their macrocycle. 2. In 2020, the synthesis of the first "higher" heterocirculenes - diazatrioxa[9]circulene and tetrahydro[10]circulene was presented. In this case, diazatrioxa[9]circulene is absolutely planar, while tetrahydro[10]circulene has a V-shaped structure. The alternation of radial (short) and endocyclic (long) bonds in the structure of the diazatrioxa[9]circulene indicates a significant contribution of the radial structure. 3. Based on the analysis of the conductivity of the newly synthesized circulenes, it was found that tetrahydro[10]circulene is a p-type semiconductor. 4. For a series of thia[7]circulenes and newly modeled Se-, Te-, S/Te- and Se/Te-substituted [8]circulenes, we have studied the aromaticity by the nucleus-independent chemical shift (NICS) method and by the method of magnetically-induced ring currents. It was established that all the studied hetero[7]circulenes and hetero[8]circulenes consist of two concentric subsystems: internal antiaromatic seven- or eight-membered ring and external aromatic system of benzene and heteroarene rings. In general, most of the studied [7]circulenes can be considered as weakly antiaromatic, while hetero[8]circulenes are aromatic. 5. It was found that the topology of the magnetically induced ring current is quite insensitive to the heteroatom type in the outer macrocycle of molecules, the number of heteroarenes and the size of the inner ring. Product Description popup.authors Ivaniuk Khrystyna B. Baryshnikova Alina T Bondarchuk Sergey V Derevyanko Victoria Yu. Karaush-Karmazin Nataliia M Litvin Valentyna A. Pikalov Ivan O. Panchenko Olexandr O. Petrova Tetiana V. popup.nrat_date 2021-02-21 Close