Metallophilic interactions and magnetism in heterobimetallic {Pt,M} lantern complexes

A small series of polymeric heterobimetallic {Pt,M} lantern complexes of the form [PtM(SAc)4DABCO]infinity (SAc = thioacetate, DABCO = 1,4-diazabicyclo[2,2,2]octane; M = Co (1), Ni (2), Zn (3)) has been synthesized, along with the discrete molecular analog of each polymer formed by replacing DABCO with quinuclidine (4-6). All compounds except 3 have been structurally characterized by single-crystal X-ray diffraction. Compound 1 shows a metallophilic Pt...Pt interaction of 3.1204(4) angstrom, while in 2 the same interaction is even shorter at 3.0944(10) angstrom. The electronic spectra of all compounds have been measured, which show d-d transitions of the 3d metal, Pt LMCT bands, and metal-metal charge transfer bands. Measurements of the temperature dependence of the magnetic susceptibility of 1 and 2 reveal antiferromagnetic exchange coupling between the 3d metal centers with J = -10 cm-1 for Co-containing 1 and J = -32 cm-1 between Ni centers for 2, both of which access the Pt...Pt metallophilic interactions.