Reactions of quadruply bonded dimolybdenum(II) and dirhenium(III) complexes with 2,6-bis(dicyclohexylphosphinomethyl)pyridine and the related behavior of the mixed P,S,P ligand bis(diphenylphosphinomethyl)sulfide

The first complexes that contain the 2,6-bis(dicyclohexylphosphinomethyl)pyridine ligand (PNP) have been isolated and characterized. The reactions of K4Mo2Cl8, (n-Bu4N)2Re2Cl8 and PdBr2(1,5-COD) afford Mo2Cl4(PNP)(HPCy2) (1), ReCl3(PNP) (2) and PdBr2(PNP) (4), respectively, while from the reaction of PNP with cis-Re2(μ-O2CCH3)2Cl4(H2O)2 the heteromacrocylic dication [Cy2P{CH2pyCH2}2PCy2]2+ has been isolated as its mixed [Cl]−/[ReO4]− salt (3). The reaction of cis-Re2(μ-O2CCH3)2Cl4(H2O)2 with bis(diphenylphosphinomethyl)sulfide (PSP) gives the mononuclear Re(V) complex ReO(OEt)Cl2(PSP) (5) in which the S atom is not coordinated. The structures of 1–5 have been established by X-ray crystallography, that of 5 being the first for a complex of this ligand.