<i>Ab initio</i> studies of structural features not easily amenable to experiment. 30. Conformational analysis and molecular structures of propanal and butanal

Abstract

Abstract The geometries of several conformations of propanal and butanal have been refined by geometrically unconstrained ab initio gradient relaxation on the 4‐21G level. Both compounds possess energy minima at OCCC torsional angles of 0° and in the 120° region, and energy maxima in the 70° region and at 180°. The structure of the aldehyde functional group is found to be relatively invariant both when different systems or when different conformations of the same system are compared. Conformationally dependent geometrical trends in propanal and butanal are discussed and found to be subtle yet noticeable.