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.