New Cluster Complexes with Octahedral Cores of Niobium Atoms: Syntheses, Structures, and Properties of [K(18-crown-6)]2[K(18-crown-6) (H2O)2]2[Nb6Cl12(CN)6] • 2CH3CN and [(C6H5)4P]4[Nb6Cl12(NCS)6] • 0.94CH3OH

The syntheses and structures of [K(18-crown-6)](2)[K(18-crown-6)(H2O)(2)](2) [Nb6Cl12(CN)(6)] center dot 2CH(3)CN (1) and [(C6H5)(4)P](4)[Nb6Cl12(NCS)(6)] center dot 0.94CH(3)OH (2), determined by X-ray single crystal diffraction, are reported. Crystal data: [K(18-crown-6)](2) [K(18-crown-6)(H2O)(2)](2)[Nb6Cl12(CN)(6)] center dot 2CH(3)CN: monoclinic, P2(1)/n, a = 17.8240(9), b = 15.9395(8), c = 18.660(1) angstrom, beta = 113.833(2)degrees, Z = 2; [(C6H5)(4)P](4)[Nb6Cl12(NCS)(6)] center dot 0.94CH(3)OH: triclinic, P (1) over bar, a = 14.6239(3), b = 14.6237(5), c = 15.9831(3) angstrom, alpha = 113.482(1)degrees, beta = 114.684(1)degrees, gamma = 92.585(1)degrees, Z = 1. Both complexes contain [Nb6Cl12Y6](4)(-) cluster anions with Y = CN and NCS, respectively, on all six cluster exo-positions. They have been prepared via ligand substitution in solution, starting from K-4[Nb6Cl18], which was synthesized by a high temperature solid state reaction. Structural trends and spectroscopic properties are discussed and compared to related compounds reported previously in the literature.