195Pt NMR spectra of ferrocenylketimine complexes of platinum(II)

The Pt-195 NMR spectra of two series of 18 ferrocenylketimine complexes of platinum(II) which include 9 cycloplatinated derivatives [sigma-Pt{(eta(5)-C5H3CMe=NAr)Fe(eta(5)-C5H5)}(DMSO)Cl] (1) and 9 coordinated compounds [trans-PtCl2(DMSO){(eta(5)-C5H4CMe=NAr)}Fe(eta(5)-C5H5)] (2) (Ar = substituted phenyl groups) have been recorded. The Pt-195 chemical shifts are regularly affected by the substituents in the N-phenyl rings, and satisfactory to excellent linear relationships are found to exist between the Pt-195 shifts (delta) and Hammett substituent constants in both series. The directions of the substituent effect on delta(Pt-195) are the same in both series, i.e., electron-donating substituents cause shifts to higher frequency, and the coordinated compounds have a better linear relationship. These Pt-195 NMR features support the existence of intramolecular coordination between the imino nitrogen atom and the platinum(II) and n-pi conjugation between the nitrogen and the N-phenyl ring. (C) 1998 Elsevier Science Ltd. All rights reserved.