Solid state electrical conductance properties of some new bimetallic salts and heterometallic coordination polymers derived from bis (1-ethoxycarbonyl-1-cyanoethylene-2,2-dithiolato) cuprate(II) ion1

This paper describes the solid state conductivity of the salt [n-Bu4N]2[Cu(ecda)2], bimetallic salts of the type, [M(diimine)3][Cu(ecda)2] and heterobimetallic coordination polymers, Pd[Cu(ecda)2] and Ag2[Cu(ecda)2] (M=Fe(II), Co(II), Ni(II), or Cd(II); diimine=1,10-phenanthroline (phen) or ethylenediamine (en) and ecda2−=1-ethoxycarbonyl-1-cyanoethylene-2,2-dithiolate) that have been synthesized and investigated using molecular spectroscopies. A unique feature of [n-Bu4N]2[Cu(ecda)2], Pd[Cu(ecda)2] and Ag2[Cu(ecda)2] is the complete quenching of paramagnetism showing the presence of strongly antiferromagnetically coupled copper(II) centres at room temperature. Temperature dependent compressed pellet conductivities of the complexes have been determined in the temperature range 303–373 K. All the complexes exhibited σrt in 10−11–10−7 S cm−1 range. The complexes [n-Bu4N]2[Cu(ecda)2], [Fe(phen)3]-[Cu(ecda)2], Pd[Cu(ecda)2] and Ag2[Cu(ecda)2] are semiconductors as their conductivity increases with the increase in temperature, with Ea=0.03–4.70 eV.