Heterometallic coordination polymers based on homo- and heteroleptic Au(III) dithiolene complexes

Two novel hetero- and homoleptic Au(III) complexes based on a dithiolene ligand bearing two 4-thiopyridyl groups have been designed, synthesized and characterized in solution and in the crystalline state. These species have been employed as metalloligands, or metallatectons, for the elaboration of heterometallic coordination polymers upon assembly with M(NCS)(2) salts (M = Mn, Co, Cd) and Co(N(CN)(2))(2) respectively. Upon combination of the neutral heteroleptic complex comprising a cyclometallating benzolh]quinoline fragment and the mononuclear Mn(NCS)(2) and Co(NCS)(2) nodes, one-dimensional coordination networks were obtained. They feature pendant heteroleptic complexes that stack centrosymmetrically in the crystalline state leading to an interdigitated system, analogous to what has been reported with the parent EDT-TTF derivative. With Cd(NCS)(2), the inorganic moieties form a two-dimensional ruffled layer with bridging thiocyanate anions, while the Aube) complexes occupy the remaining apical positions of the Cd(s) centers. This leads to a stacking of the heteroleptic species. With the homoleptic complex, a monoanionic analogue of a symmetrical TTF, a two-dimensional coordination network was obtained by combination with Co(N(CN)(2))(2), featuring one dimensional [Co(N(CN)(2))](alpha) chains. These networks have been characterized in the crystalline state by X-ray diffraction and represent, to the best of our knowledge, the first heterometallic coordination polymers based on Au(III) dithiolene complexes and transition metal cations.