The reactivity of [Pt2(μ-S)2(PPh3)4] towards difunctional chloroacetamide alkylating agents: Formation of cyclized or bridged products

The reactions of [Pt2(μ-S)2(PPh3)4] towards some bis(chloroacetamide) alkylating agents have been investigated. Reaction with one mole equivalent of the hydrazine-derived compound ClCH2C(O)NHNHC(O)CH2Cl led to the cyclized product [Pt2{SCH2C(O)NHNHC(O)CH2S}(PPh3)4]2+ which showed two different PPh3 environments in the 31P{1H} NMR spectrum, as a result of non-fluxional behavior of the dithiolate ligand in solution. Reactions of [Pt2(μ-S)2(PPh3)4] with the ortho and para isomers of the phenylenediamine-derived bis(chloroacetamides) ClCH2C(O)NHC6H4NHC(O)CH2Cl gave tetrametallic complexes containing two {Pt2S2} moieties spanned by the CH2C(O)NHC6H4NHC(O)CH2 group. Both the ortho and para isomers were crystallographically characterized; in the ortho isomer there is intramolecular CO···H–N and S···H–N hydrogen bonding involving the two amide groups.