Comparative XPS, NMR and IR study of the back-bonding to the carbonyl groups in (C 6H 5) 3− nPX nCr(CO) 5 derivatives (X  Cl, Br, I, H; n = 0−3)

Abstract

Linear correlations are shown to exist between the characteristic infrared CO frequency ν(CO) A 1 (eq.), the carbonyl carbon NMR chemical shift δ13 C(CO) and the XPS Cl s(CO) and 01 s(CO) binding energy for the compounds with general formula (C 6H 5) 3 nPX nCr(CO) 5 (X  Cl, Br, I, H; n = 0−3). This is considered sufficient proof that these experimental parameters can be used as a measure of the ( d Cr → π*)π back-bonding in these complexes.