Synthesis and crystal structure of oxonitrate complexes Cs[VO2(NO3)2], Cs[MoO2(NO3)3], and MoO2(NO3)2

Cs[VO2(NO3)2] (I), MoO2(NO3)2 (II), and Cs[MoO2(NO3)3] (III) complexes have been obtained by crystallization from nitric solutions and studied by single-crystal X-ray diffraction. Complexes I and II contain infinite zigzag chains of similar compositions, [VO2(NO3)2]− and [MoO2(NO3)2], in which V and Mo atoms form, respectively, trigonal- and pentagonal-bipyramidal polyhedra. Each of these polyhedrons also contains one terminal and two bridge O atoms and two terminal NO3 groups which are monodentate and bidentate in complexes I and II, respectively. Complex III has an island structure and consists of Cs+ cations and [MoO2(NO3)3]− anions, in which the Mo atom is surrounded by one bidentate NO3 group and two monodentate NO3 groups and two terminal O atoms in the cis-positions; oxygen atoms form a polyhedron in the form of distorted octahedron. According to the ab initio calculation of isolated MoO2(NO3)2 molecules in the gas phase and solution, the coordination environment of the Mo atom, similarly to the Cr(VI) atom in CrO2(NO3)2, is formed by two bidentate nitrate groups and two terminal O atoms (polyhedron- twisted trigonal prism).