Inorganic Chemistry, Vol.41, No.7, 1824-1830, 2002
N-centered hexazirconium chloride clusters: Excision and redox chemistry
The tightly cross-linked solid Zr6Cl15N yields [(Zr6NCl12)Cl-6](3-) upon heating with bis(triphenylphosphine)iminium chloride (PPNCl), in MeCN at 90 degreesC. Purple solutions containing [(Zr6NCl12)Cl-6](3-) were obtained and characterized with N-15 NMR. Cyclic voltammetric (CV) measurements on the series of [(Zr(6)ZCl(12))Cl-6](n-) cluster ions (Z = Be, B, C, and N) in acetonitrile reveal that these cluster ions exhibit multiple reversible redox waves at potentials that can be systematically understood, including a reversible redox wave corresponding to the [(Zr6NCl12)Cl-6](3-/4-) couple. Preparation of the reduced cluster ion, [(Zr6NCl12)Cl-6](4-), (with 15 cluster-bonding electrons) was achieved by reduction of [(Zr6NCl12)Cl-6](3-) with (C-5(CH3)(5))(2)Co. Several new N-centered cluster complexes: (PPN)(3)[(Zr6NCl12)Cl-6].CH2Cl2, [(C-5(CH3)(5))(2)Co+](3)[(Zr6NCl12)Cl-6], and (Et4N)(4)[(Zr6NCl12)Cl-6].2CH(3)CN have been isolated and structurally characterized.