Vanadium Polyoxoanions within Coordination Polymers Based on a Macrocyclic Nickel Complex: Structural Diversities and Single-Crystal to Single-Crystal Transformation

摘要

Five three-dimensional (3D) coordination polymers, {(NiL)[(NiL)(V16O42)]}(n)center dot 2nH(2)O (1), [(NiL)(3)(VO3)(6)](n)center dot 5nH(2)O (2), [(NiL)(3)(V6O18)](n)center dot 7nH(2)O (3), [(NiL)(3)(V8O23)](n) (4), and [(NiL)(4)(V(10)O2(9))](n) (5), have been obtained by the reaction of the macrocyclic nickel complex [NiL](ClO4)(2) (L = 1,4,8,11-tetraazacyclotetradecane) with NH4VO3 under different conditions. Single-crystal X-ray diffraction analyses revealed that the [VO3](-) anion assumes diverse species and structures in these five coordination polymers, including the [V16O42](n)(4n-) sheet, [V6O18](6-) ring, [VO3](n)(n-) chain, [VO3](n)(n-) sheet, and [V10O29](n)(8n-) chain. The [V16O42](n)(4n) -sheets, [V6O18](6)(-) rings, [VO3](n)(n-) chains, [VO3](n)(n-) sheets, and [V10O29](n)(8n-) chains are linked together through [NiL](2+) bridges to form the 3D frameworks of 1-5. The single-crystal to single-crystal transformation between 2 and desolvated 2 was successfully realized. Electrochemical measurements indicate that 2 and 4 are potential catalysts for water splitting.