Nine-coordinated Ag~+ ion in a diamondoid 3D all-inorganic framework constructed from α-metatungstate anions and Ag~+ ions: Synthesis and structure of [{Ag(H_2O)_3(Bu~iNH_2)_4}_2Na_2H_2(H_2W_(12)O_(40))] .4H_2O

摘要

A 3D organic—inorganic compound based on Ag~+ ion and α-metatungstate polyoxometalate (POM), [{Ag (H_2O)_3(Bu~ iNH_2)_4}_2Na_2H_2(H_2W_(12)O_(40))].4H_2O (1), was synthesized and characterized by elemental analysis, IR, UV, TG and single crystal X-ray diffraction. The [H_2W_(12)O_(40)]~)6-) (W_(12)) anion as tetradentate ligand coordinates to four Ag~+ ions which in turn bridges two W_(12) anions, leading to a novel 3D all-inorganic framework. Ag~+ ion exhibits an unusual coordination number of nine with a mono-capped square antiprism geometry. The ligand, isobutyl amine, was in situ formed from nicotinic acid and did not anticipate in the formation of the framework. The title compound represents the first 3D all-inorganic covalent framework by combination of a-metatungstate anions [H_2W_(12)O_(40)]~(6-) with Ag~+ ions in aqueous solution.