Hydroxy-group stretching bands and conformations of substituted benzyl alcohols

Abstract

The O–H stretching absorptions of aryldi-t-butylmethanols are composed of three symmetrical bands. These are assigned to antiperiplanar H–O–C–Ar arrangement, and two synclinal forms which are distinguished by the presence or absence of O–H ⋯π-electron interaction. N.m.r. evidence suggests that interconversion between the synclinal forms, involving only a partial rotation about the Ar–C axis, is rapid at 34 °C; complete rotation is more severely impeded.

The measurement of enthalpy differences confirms the occurrence of intramolecular bonding in benzyl alcohol and dimethylphenylmethanol.