Synthesis and crystal structure of the new binuclear complex of cerium(III) nitrate with 4,4,10,10-tetramethyl-1,3,7,9-tetraazospiro[5.5]undecane-2,8-dione and the change in the periodical properties in isostructural series of lanthanide complexes with this ligand

Abstract

The centrosymmetrical binuclar complex of cerium(III) nitrate with bicyclic bis-urea 4,4,10,10-tetramethyl-1,3,7,9-tetraazospiro[5.5]undecane-2,8-dione or spirocarbone (Sk), [Ce(C11H20N4O2)(H2O)2(NO3)3]2 (I), is synthesized for the first time, and its structure is determined (CIF file CCDC 985758). The crystals of compound I are monoclinic: space group P21/n, a = 14.2797(13), b = 7.3922(6), c = 21.003(2) A, β = 102.103(10)°, V = 2167.8(3) A3, ρcalcd = 1.85 g/cm3, Z = 2. The cerium atom is coordinated by two oxygen atoms of two Sk molecules bound by the symmetry procedure (1 − x, −y, 1 − z), three bidentate nitrate anions, and two water molecules. The coordination polyhedron of the cerium atom is an irregular ten-vertex polyhedron. The Ce…Ce distance in the complex is 9.57 A. The change in the periodical properties in a series of the Sk complexes with lanthanide(III) (Ce-Lu, except for Pm) nitrates is discussed.