Conducting properties of new heterometallic one-dimensional coordination polymers derived from 1-nitroethylene-2,2-dithiolate (NED2−) ligand and their I2-doped products

Four new heterometallic coordination polymers of general formula [M2′M(NED)2] (M = Ni(II), M′ = Ag(I) 1 or Tl(I) 2; M = Cu(II), M′ = Ag(I) 3 or Tl(I) 4; NED2− = 1-nitroethylene-2,2-dithiolate) have been synthesized and characterized by elemental analyses, IR, ESR, UV–vis and magnetic susceptibility measurements. Powder XRD patterns of the compounds (1–4) show them virtually isostructural and significantly differ from those of their I2-doped products. All the compounds are weakly conducting at room temperature with σrt ≈ 10−12 S cm−1 and show behavior of semiconductors in the 300–420 K temperature range. Notably the conductivities of the I2-doped derivatives show an enhancement of 103 order of magnitude and also exhibit semiconducting properties.