Addition reactions of primary and secondary aliphatic amines to the benzonitrile ligands in cis- and trans-[PtCl2(NCPh)(2)] complexes. X-ray structure of the amidine complex trans-[PtCl2{Z-N(H)=C(NHBut)Ph}(2)]

The reactions of cis-[PtCl2(NCPh)(2)] with a fivefold excess of the primary aliphatic amines RNH2 (R = Me, Et, Pr-i) in CH2Cl2 at -10 degreesC afford in high yield the di-amidine complexes cis-[PtCl2{N(H)=C(NHR)Ph}(2)]. The reaction of cis-[PtCl2(NCPh)(2)] with (BuNH2)-N-t yields the di-amidine complex traps-[PtCl2{Z-N(H)=C(NHBut)Ph}(2)] which has been characterized also by an X-ray diffraction analysis. The corresponding reactions of trans -[PtCl2(NCPh)(2)] with a fivefold excess of RNH2 (R = Me, Et) afford the di-amidine derivatives trans -[PtCl2{N(H)=C(NHMe)Ph}(2)], while the reactions of (PrNH2)-N-i and (BuNH2)-N-t lead, for the former, to a mixture of the mono-amidine derivative trans -[PtCl2(NCPh){N(H)=C(NHPri)Ph}] and the di-amine dicationic species derivative trans -[Pt((PrNH2)-N-i)(2){N(H)=C(NHPri)Ph}[Cl](2) and, for the latter, to the mono-amidine complex derivative trans-[PtCl2(NCPh){N(H)=C(NHBut)Ph}]. The reactions of cis- or traps-[PtCl2(NCPh)(2)] di-nitrile complexes with the secondary aliphatic amine Me2NH yields the di-amidine complexes cis- or traps-[PtCl2{N(H)=C(NMe2)Ph}(2)], while the corresponding reactions with RR'NH (R, R' = Me, Et; R = Me, R' = Bu-t) produce the mono-amidine complexes cis- or trans-[PtCl2(NCPh){N(H)=C(NRRt)Ph}]. The stereochemistry of the amidine ligands in the final products has been investigated by H-1 NMR spectroscopy. (C) 2002 Published by Elsevier Science B.V.