Coordination polymers from 1,3,4‐thiadiazole‐2,5‐dithiol and metal ions

Abstract

Abstract The copolymerization of 1,3,4‐thiadiazole‐2,5‐dithiol (bismuthiol) with 1+, 2+, and 3+ valent metals is reported. Polymerization conditions were mimicked by means of Job's technique of solutions mixing. The polymers in aqueous solutions do not conduct electricity, but electrolytes are formed in proportion to polymer formation and the pH changes. The metal concentration in solutions confirms the metal‐ligand stoichiometry. The UV absorption of the ligand (at 320 nm) decreases and light scattering by polymer (at 380 nm) increases with polymer formation. The stoichiometry of polymers (obtained from the conductivity inflection point and metal analysis) is as follows. Mt 2+ : bismuthiolate = 1 : 1; Al 3+ : bismuthiolate = 2 : 3 and Ag + : bismuthiolate = 2 : 1. Equations describing polymer formation on the basis of the solution conductivities are presented, and a model of polymer formation is proposed. It is concluded that 2+ valent metals from linear polymers but Al 3+ forms branched polymers.