Molecular structures of o- and m-fluoro(trifluoromethoxy)benzenes according to gas electron diffraction and quantum-chemical studies: Comparison of the structures of trifluoromethoxybenzene and its fluorinated derivatives

摘要

The geometric structures and conformations of o-fluoro(trifluoromethoxy)benzene (o-F-C6H4OCF3) and m-fluoro(trifluoromethoxy)benzene (m-F-C6H4OCF3) molecules were studied using gas electron diffraction and high-level quantum-chemical calculations. It was demonstrated that, in the gas phase, o-F-C6H4OCF3 molecules exist as the orthogonal conformer and m-F-C6H4OCF3 molecules exist as a mixture of conformers dominated by the orthogonal conformer. Main geometric parameters were determined for o-F-C6H4OCF3 and m-F-C6H4OCF3. The comparative analysis of the conformations of fluorine-substituted anisoles demonstrated that the main conformer in the studied compounds is the orthogonal conformer, unlike anisoles, for which the planar conformer is predominant.