Influence of pressure on molecular packing and photochemical properties in three chalcone analogs

Abstract

Abstract The structures of 1-(4-methylphenyl)-3-(2-thienyl)prop-2-en-1-one, (I), 1-(5-bromo-2-hydroxyphenyl)-3-(2-furyl)prop-2-en-1-one, (II), and 1-(3-furyl)-3-[3-(trifluoromethyl)phenyl]prop-2-en-1-one, (III), were determined in ambient and high pressure conditions. The values of the intermolecular geometrical parameters describing possibilities of execution of [2+2] photodimerization were calculated and analysed. In the case of ambient pressure, for (I) they are close to the border valid for photoreactive compounds and for (II) and (III) they exclude the photochemical reaction in crystals. High pressure hardly changed the mutual orientation of adjacent molecules and largely the distance between them: in the case of (I), the distance was far below limits for compounds undergoing [2+2] photodimerization. The volume of free space was calculated for the studied compounds for different values of pressure and analysed in the context of possibilities of the [2+2] photodimerization.