Unusual coupling constants nJ(195Pt—1H) and Pt↼H—C interactions in new Schiff base complexes of N-alkyl-1-(ferrocen-1-yl)methanimine

A series of novel ferrocenylimine complexes of platinum(II) ethene of general formula trans-[PtCl2(η2-C2H4) (imine)], imine = N-alkyl-1-(ferrocen-1-yl)methanimine, (alkyl = Me; i-Pr, i-Bu, s-Bu, t-Bu, ±CH(Me)Ph, CH2Ph and Ph) have been prepared and characterized by elemental analysis, i.r, 1H-, 13C-n.m.r. spectra (15N- and 195Pt-n.m.r. in part). Unusual coupling constants 3J(195Pt—1H), 92–98 Hz were observed between the imino proton H6 and platinum(II) which are too large for three bond coupling constants, thereby suggesting a Pt↼H—C interaction.