Molecular structures and conformations of 4-fluoranisole and 3,4-difluoranisole: gas electron diffraction and quantum chemical calculations

The molecular structures and conformational properties of 4-fluoroanisole and 3,4-difluoroanisole were studied by gas electron diffraction and quantum chemical methods (HF, MP2 and B3LYP with 6-31G* basis sets). 4-Fluoroanisole exists as a single conformer with the O–CH3 bond in the plane of the aromatic ring. Two planar conformers with nearly equal amounts were derived for 3,4-difluoroanisole. q 2004 Elsevier B.V. All rights reserved