CRYSTAL-STRUCTURE OF TETRAKIS(DIPICOLINATO)TRIURANYL

H2[(UO2)3(C7H3NO4)4] . 2H2O, M(r) = 1508.55, monoclinic, P2(1)/n, a = 8.881(6), b = 9.349(6), c = 21.458(6) angstrom, beta = 98.18(4)-degree s, V = 1763.5 angstrom3, Z = 2, D(x) = 2.842 Mgm-3, lambda(MoK(alpha)) = 0.71069 angstrom, mu = 13.1 mm-1, F(000) = 1444, room temperature, R = 0.066 for 2541 observations with I > 3sigma(I). In the trimer, two of the uranyl groups have a pentagonal bipyramid coordination polyhed ron with one dipicolinate acting as a terdentate ligand, and two monod entate dipicolinate donors while the third uranyl has a hexagonal bipy ramid coordination polyhedron with two terdentate dipicolinate ligands saturating the equatorial plane. The three units are linked together via bridging with carboxylate groups. Bond lengths and bond angles con form well with other data for typical hexa and penta coordinated urany ls.