Charge Ordering and Carrier Generation by Air Oxidation of a Nickel Complex with Selenium-Containing Extended-Tetrathiafulvalenedithiolate Ligands

The structures and electrical properties of (nBu4N)­[Ni­(dmstfdt)2] (1), (nBu4N)2[Ni­(dmstfdt)2] (2), and (nBu4N)3[Ni­(dmstfdt)2]2 (3), where dmstfdt = extended-tetrathiafulvalenedithiolate ligand, were examined. The fresh crystal of 1 was found to be a Mott insulator, but the crystal gradually became highly conducting because of air oxidation. Compound 3 exhibited a semiconducting charge-ordering state.