Structural and Spectral Properties of Photochromic Diarylethenes: Size Effect of the Ethene Bridge

Autor:	Yulia V. Nelyubina, Andrey G. Lvov, Anatoly V. Metelitsa, Alexey M. Kavun, Vadim V. Kachala, Valerii Z. Shirinian
Rok vydání:	2017
Předmět:	010405 organic chemistry Hydrogen bond Organic Chemistry Cyclohexene 010402 general chemistry Photochemistry 01 natural sciences 0104 chemical sciences NMR spectra database chemistry.chemical_compound Photochromism chemistry Intramolecular force Thiophene Cyclopentene Hypsochromic shift
Zdroj:	The Journal of Organic Chemistry. 82:1477-1486
ISSN:	1520-6904 0022-3263
DOI:	10.1021/acs.joc.6b02665
Popis:	The effect of the size of the ethene bridge on the structural and spectral properties of photochromic diarylethenes, which remains a poorly understood phenomenon, was studied as applied to diarylethenes containing unsymmetrical (cyclohexenone and cyclopentenone) and symmetrical (cyclohexene and cyclopentene) ethene bridges. Thiophene, oxazole, and imidazole derivatives were used as aryl moieties. An increase in the size of the ethene bridge in the cycloalkenone series was found to be accompanied by a hypsochromic shift of the absorption maximum of the photoinduced form, whereas no difference was found for cycloalkenes. A detailed analysis of the NMR spectra (including 2D experiments) revealed previously unknown effects associated with the existence of an intramolecular hydrogen bond (CH···N) between the six-membered ethene bridge and the azole substituents. The NMR experimental data obtained were confirmed by DFT quantum chemical calculations and X-ray analysis. It was found that an intramolecular hydrogen bond favors an increase of the quantum yield of the photocyclization reaction.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::0658af9ebbf72b064a586db0e6e7bb03 https://doi.org/10.1021/acs.joc.6b02665 Zobrazit plný text záznamu