Kernresonanzspektroskopische Untersuchungen (1H-, 13C-, 31P-, 195Pt-NMR) an Alkinyl-Komplexen von PtII, PdII und NiII / Nuclear Magnetic Resonance (1H-, 13C-, 31P-, 195Pt-NMR)-Studies of Alkynyl Derivatives of PtII, PdII and NiII

Abstract

The NMR parameters (1H, 13C, 31P, 195Pt) of compounds of the type cis- and trans- [M(C≡C-R)2(PR′3)2] (M = Ni, Pd, Pt) are reported. The chemical shifts δ13C (M-C≡C; R) and δ195Pt (together with UV data) indicate the presence of π-backbonding from the metal into π*C≡C the orbitals. This also explains some unusual features of the coupling constants J(≡13C1H), J(13C≡13C) and J(195Pt13C≡). The NMR parameters reflect an increase in the amount of π-backbonding for Pt < Pd < Ni.