Halido‐Bridged 1D Mixed‐Valence CuI–CuII Coordination Polymers Bearing a Piperidine‐1‐carbodithioato Ligand: Crystal Structure, Magnetic and Conductive Properties, and Application in Dye‐Sensitized Solar Cells

Abstract

AbstractNew mixed‐valence CuI–CuII 1D coordination polymers of the structure [CuI2CuIIX2(Pip‐dtc)2(CH3CN)2]n [Pip‐dtc = piperidine‐1‐carbodithioate; X = Br (1a), I (1b)] containing a dithiocarbamate derivative have been synthesized and structurally characterized by X‐ray diffraction. The 1D infinite chains were formed from mononuclear copper units [Cu(Pip‐dtc)2] connected by bromido‐ or iodido‐bridged copper dinuclear units that include acetonitrile ligands {i.e., [Cu2X2(CH3CN)2]}. Evaluation of the magnetic properties of 1a and 1b revealed that these complexes displayed relatively strong antiferromagnetic interactions [J = –20.4 cm–1 (1a) and J = –18.8 cm–1 (1b)] between unpaired electrons of the copper(II) ions through the dinuclear halido–copper(I) units. Impedance spectroscopy revealed that complexes 1a and 1b exhibit intriguing semiconducting properties at activation energies of Ea = 0.78 eV (1a) and Ea = 0.62 eV (1b). Coordination polymers 1a and 1b were then adopted as the sensitizing material in dye‐sensitized solar cells (DSSCs).