Stereochemical investigation of the addition of amines to platinum(II)-coordinated nitriles. Synthesis, characterization and X-ray structure of the amidine complex cis-[PtCl2{E-N(H)=C(NMe2)Me}2].CH2Cl2

The reaction of cis-[PtCl2(NCMe)2] with a 5-fold excess of Me2NH in CH2Cl2 at – 10 °C affords in high yield the bis-amidine complex cis-[PtCl2{E-N(H)=C(NMe2)Me}2] (E,E-2), where both the amidine ligands assume the E configuration. E,E-2 was characterized by X-ray structure analysis in the solid state, NMR spectroscopy in solution and electrospray ionization mass spectrometry (ESI-MS) in the gas phase. The corresponding reaction of trans-[PtCl2(NCMe)2] with a 5-fold excess of Me2NH gave mainly the bis-amidine complex trans-[PtCl2{E-N(H)=C(NMe2)Me}2] (E,E-3) together with the mono-amidine derivative trans-[PtCl2{E-N(H)=C(NMe2)Me}(NCMe)] (E,E-4).