From an antiferromagnetic insulator to a strongly correlated metal in square-lattice MCl2(pyrazine)2 coordination solids

Achieving high conductivity in metal-organic solids can be challenging, due to the difficulty of obtaining a good overlap between the d-orbitals of the metal and the π-orbitals of the organic molecule. Here, the authors present two coordination solids, VCl2(pyrazine)2 and TiCl2(pyrazine)2, with remarkably different electrical conductivity. While the former is an insulator, the latter displays the highest conductivity of any octahedrally coordinated metal ions based metal-organic solid.