Design and properties of mixed metal multinuclear molecules: Part 1. Molecular structures of [Ag(PR3)2]2[Ni(mnt)2] type complexes (R=Me, Et, Cy and mnt=maleonitriledithiolate) and [AgL]2[Ni(mnt)2] type complexes with chelating diphosphines (L=dppf and dpp

The trinuclear complexes [Ag(PR3)2]2[Ni(mnt)2] and [AgL]2[Ni(mnt)2] have been prepared by reactions of (NEt4)2[Ni(mnt)2] and Ag2SO4 with alkyl phosphines (PR3=P(CH3)3 (PMe3) for 1, P(C2H5)3 (PEt3) for 2 and P(C6H11)3 (PCy3) for 3), or with chelating diphosphines (L=1,1′-bis(diphenylphosphino)ferrocene (dppf) for 4 and bis(diphenylphosphino)methane (dppm) for 5). The structures of all the complexes have been determined by X-ray crystallography. Interactions between the [Ag(PR3)2]+ and [Ni(mnt)2]2− groups occur in compounds 1 and 2 with NiAg distances of 3.063(4) and 2.9311(6) Å, respectively. Only one sulfur atom of each mnt ligand bridged [Ag(PR3)2]+ cations and [Ni(mnt)2]2− anions in compound 1 through 3 with AgS distances of about 2.7 Å. There is no interaction between Ag and Ni in compound 3 due to the flexibility of the cyclohexyl groups. Interactions between [AgL]+ and [Ni(mnt)2]2− groups also occur in compound 4 with a much shorter AgNi distance of 2.7213(7) Å, while silver atoms and the NiS4 plane in compound 4 make a chair conformation with AgS distances of about 2.8 Å. In compound 5, dppm bridges two silver atoms, and interaction between silver atoms occurs at a distance of 2.9859(11) Å, and only one sulfur atom of mnt is used to bridge Ni and Ag atoms with AgS distances of 2.582(3) and 2.663(3) Å.