Protonation of metal carbonyl complexes : I. An infrared study of the arenechromium tricarbonyl and arenechromium dicarbonyl triphenylphosphine complexes

Abstract

Through the use of IR spectroscopy, protonation of arenechromium dicarbonyl triphenylphosphine complexes in trifluoroacetic acid and in mixtures of the latter with methylene chloride, has been shown to occur at the metal atom. No protonation of arenechromium tricarbonyls appears to occur under similar conditions. The ease of protonation appears to increase with the introduction of increasing electron-releasing substituents into the π-bonded aromatic ring.