Structure of diethyl glaucophanic enol in the crystal, and in solvents of differing polarities
Abstract
Black diethyl glaucophanic enol crystals have a ‘staircase’ arrangement of molecules connected by self charge-transfer interactions and display semi-conductance: in dry less-polar solvents 1H n.m.r. and u.v. data support the unsymmetrical enol structure (1) but in polar solvents the structure is symmetrical (2): comment is made on other glaucyrones, one of which exists in the 7′-H-form in CDCl3.