Спектральна характеристика та електронна будова синтетичних похідних кумарину. Повідомлення І. Вивчення УФ-спектрів і електронної будови кумарину та 4-оксикумарину

Abstract

Coumarin and 4-oxycoumarin were investigated UV-spectrums of light absorption in 95% alcohol as a model of compounds for fur ther studying of electrical spectrums dicoumarin, neodicoumarin, fepromaron, sinkumar and varfarin natrium klatrat. On a spectral curve of unsubstitued coumarin observed two intensive maximums. Oxygroup introduction to 4 molecules of coumarin causes splitting of a maximum on two parts: hypsochromic shift and the formation of the bend at 274 nm. Quantum-chemical calculations of electric density of coumarin indicate about effect on the electrofeelic cubstitution reactions on C8- and C10-atoms. Presence of the alkene fragment causes the reactions of electrofeelic addition. OH-group presence in the forth-positions oxycoumarin, lacton ring of the molecule and increases the electron densiy in the aromatic ring. The presence of keto-enol thautomerism of 4-oxycoumarin provides the possibility of interaction reagents in reactions such as AE and SN.