STUDY OF NICKEL-CARBON BONDING BY X-RAY PHOTOELECTRON-SPECTROSCOPY .1.

X-ray photoelectron spectroscopy (XPS) nickel 2p 3 2 binding have been measured for a series of trans square-planar Ni(X)(Y)(PEt3)2 complexes and correlated with a calculated 'charge parameter' for the nickel atoms. A reasonbly good correlation exists when X or Y is chloro, alkyl, vinyl, acyl, or phenyl, but not when both X and Y are acetylide. The deviation of ther diacetylide complex from the correlation is attributed to a substantial π character in the nickelcarbon bonds. The agreement of the aryl, vinyl, and acyl complexes with the correlartion indicates that any π character in these nickelcarbon bonds is small. © 1979.