Carbon-13 nuclear magnetic resonance spectra of 1-p-tolylethyl- and di-p-tolylmethyl-tricarbonylchromium cations

Abstract

The 13C n.m.r. spectra of 1-p-tolylethyl- and di-p-tolylmethyl-tricarbonylchromium cations and of the analogous complexed alcohols have been obtained. The chemical shifts compared with those of the corresponding uncomplexed cations are explicable in terms of structures in which the positive charge is localized on the tricarbonylchromium system to a great extent. From an analysis of the behaviour upon variations of temperature of the non-equivalent splittings of the ortho- and meta-carbons as well as of the carbonyl resonance one can deduce that two motions, around the aryl–methyl and the metal–ring bonds, characterize the dynamics of the ions.