Structural Insights into In Situ Disulfide Bond Formation for Enhancing Schottky Diode Behavior of a Paddle-Wheel Zn-Based Coordination Polymer

In the present study, a one-dimensional (1D) Zn(II)-based paddle-wheel coordination polymer [Zn(2,2′-dsb)(4-phpy)] (1) [H22,2′-dsba = 2,2′-disulfanediyldibenzoic acid and 4-phpy = 4-phenylpyridine] has been fabricated using a slow diffusion method at room temperature. Here, the monomeric ligand 2-mercaptobenzoic acid (2-mba) produces in situ dimeric 2,2′-dsba ligand via S–S bond formation, which ultimately generates a 1D cyclic loop chain structure. The structural feature originating from the formation of S–S bond significantly influences the electrical conductivity of the material, which exhibits semiconducting nature and reveals Schottky barrier diode behavior. Semiconducting nature of the compound is documented by density functional theory calculation and current density–voltage (I–V) characteristics.