The non-coincidence effect in binary mixtures: is a sign inversion with dilution fake or reality?

Abstract

This study investigates whether benzene may be effective in promoting the sign inversion of the non-coincidence effect of the carbonyl stretching mode, v₃(C=O), of acetone in the high dilution regime, as claimed in literature. We have found that benzene leaves the non-coincidence effect positive in the whole concentration range and unaltered with respect to that already observed in acetone/CCl₄ mixtures at high dilution, although slightly reinforcing it. The applicability of available theories to the concentration dependence of the non-coincidence effect in benzene is discussed.