Hydrothermal synthesis and crystal structure of a new molybdenum(VI) arsenate(III), Co-III(en)(3)H3O[((CoO6)-O-II)(Mo6O18)-O-VI((As3O3)-O-III)(2)]center dot 2H(2)O

A new molybdenum arsenate, Co-III(en)(3)H3O[((CoO6)-O-II)(Mo6O18)-O-VI((As3 O3)-O-III)(2)]. 2H(2)O, has been hydrothermally synthesized and characteriz ed by single-crystal X-ray diffraction and thermogravimetric analysis (TGA) . The polyanion framework derives from the Anderson structure in which the central octahedron is filled up by a cobalt(II), and is capped on both side s by two cyclic As3O6 groups. The countercations contain a [Co(en)(3)](3+) complex cation and a proton hydrate H3O+. There are hydrogen bonds between the countercations and polyanions. A probe reaction of the oxidation of ben zaldehyde with H2O2 shows that the title compound has high catalytic activi ty in the reaction. (C) 1999 Elsevier Science S.A. All rights reserved.