Molecular Kerr constants and structures of complexes of carboxylic acids

Abstract

are possible: a centrosymmetr ic arrangement with atoms of the ring in one plane, or an arrangement with the mole cules combining to form the ring at smal l angles with respect to each other. In the first case, the dipole moment of the dimer p dim should be zero, and in the second case the complex should be polar. Since values of dipole moment do not allow an unambiguous solution of this problem [ t , 2], it was of interest to compare the observed "molecular" Kerr constants of the earboxyl ic acids with values ca lcu la ted for the conformations of cyc l ic complexes mentioned. Accordingly, values of(mK 2) for acet ic acid were determined by the method of di lute solutions in two solvents: benzene, where the molecules were found pr incipal ly in the form of cyc l ic dimers, and in dioxane, where these dimers were absent and the ac id molecules formed complexes of the type