Crystal Structure of [Ru(terpy)(2)](0): A New Crystalline Material from the Reductive Electrocrystallization of [Ru(terpy)(2)](2+).

Reductive electrocrystallization of Ru(terpy)(2)(2) (where terpy = 2,2':6',2' '-terpyridine) from an acetonitrile solution containing 100 mM TBAPF(6) results in the formation of black crystals. Crystal data: [Ru(terpy)(2)].(PF(6))(2)[(CH(3))(2)CO], monoclinic, space group P2(1)/c with a = 20.801(2) Å, b = 8.943(1) Å, c = 19.453(2) Å, beta = 92.524(9) degrees, and Z = 4; [Ru(terpy)(2)] (1), orthorhombic, Fdd2 with a = 39.757(4) Å, b = 56.464(6) Å, c = 8.507(1) Å, and Z = 32. X-ray analysis reveals that the crystals consist exclusively of Ru(terpy)(2) (1), with no solvent or counteranion present in the lattice. Ru(terpy)(2) units are structurally very similar to the parent Ru(terpy)(2), with nearly perfect octahedral symmetry around the metal center and with two terpy ligands that are basically planar. Analysis of the crystal packing shows that Ru(terpy)(2) crystals have close intermolecular distances, while Ru(terpy)(2) crystals show only intermolecular interactions along the c axis with contacts that are less than 3.5 Å. Analysis of molecular volumes and empty spaces reveals the presence of cavities, which could contain substantial electron density.