CRYSTAL AND MOLECULAR-STRUCTURE OF THE COMPLEX NEPTUNIUM(V) ACETATE [(NPO2)(2)(CH3COO)(2)H2O].C2H3N

The synthesis and crystal structure (CAD4 autodiffractometer, lambda M oKalpha radiation) of [(NpO2)(2)Ac2H2O]. C2H3N are described. Crystal data: a = 25.311(9), b = 6.782(2), c = 8.065(3) Angstrom, V = 1384.4(8 ) Angstrom(3), space group Pnma, Z = 4, R = 0.046, R(w) = 0.046 for 15 05 independent reflections. The structure is based on neutral layers p arallel to the (100) plane with the composition [Np(1)O2Np(2)O2Ac(1)Ac (2)H2O](n). Acetonitrile molecules are located in the interlayer space . The coordination polyhedron of the Np(1) atom is pentagonal bipyrami d (coordination number 7), and that of the Np(2) atom is a derivative of pentagonal bipyramid (coordination number 8) incorporating coordina ted water molecule. In a layer, bidentate dioxo cations Np(1)O-2(+) an d Np(2)O-2(+) are associated by cation-cation bonds into neptunium-oxy gen network, in which rhombic prisms of 8 Np atoms may be distinguishe d. Geometric characteristics, features of the structure, and propertie s of the compound are discussed.