Synthesis of saturated Curtis-type Ni derivatives as dithioxalate–perchlorate: Thin film by vacuum thermal evaporation and electrical and optical evaluation

The bridge [Ni(racMe6[14]aneN4](C2S2O2)·2(ClO4) has been synthesized by coupling reactions of monomers [Ni(racMe6[14]aneN4](ClO4)2 containing the central metals in the oxidation state II+, with molecules of dithioloxalic acid dipotassium salt (C2S2O2)K2, to obtain a stacked arrangement that exhibits electrical properties. The synthesized powder and thin films of this material, deposited by vacuum thermal evaporation, show the same intra-molecular bonds as is shown by IR spectroscopy studies, which indicates that thermal evaporation does not alter these bonds, but thin films are amorphous. The effect of temperature on the conductivity has been measured in thin films (∼419 nm in thickness) deposited by vacuum thermal evaporation. They show a typical semiconductor behavior with an activation energy of 0.22 eV. The optical band gap was determined and found to be 2.2 eV and arose from indirect transitions.