QUANTUM-CHEMICAL INVESTIGATIONS OF STRUCTURE AND SPECTRAL PROPERTIES OF 2-(3-COUMAROYL)BENZOPYRYLIUM CATIONS

Abstract

Spectral properties of 2-(3-coumaroyl)benzopyrylium cations and their nucleophilic complexes with acetonitrile molecules were studied using DFT and TD DFT methods. It was found that the ground state of the cations studied is characterized by the presence of two conformers with different distribution of the positive charge between the benzopyrylium and coumarine fragments. There are three such conformers in the excited state. The spectral characteristics of the more stable conformers were calculated. It was demonstrated that 2-(3-coumaroyl)benzopyrylium cations in both in solution and gas phase can exist only in the form of the most stable conformer. The formation of nucleophilic complexes of 2-(3-coumaroyl)benzopyrylium cations with acetonitrile molecules was modeled. It was found that the anomalous spectral properties of 2-(3-coumaroyl)benzopyrylium salt solutions are connected to the formation of nucleophilic complexes with the solvent.

How to Cite
Sanin, E. V.; Novikov, A. I.; Roshal, A. D. Chem. Heterocycl. Compd. 2014, 50, 371. [Khim. Geterotsikl. Soedin. 2014, 404.]

For this article in the English edition see DOI 10.1007/s10593-014-1485-4