Synthesis and molecular and crystal structure of the coordination metallopolymer of scandium(III) nitrate with 4,4,10,10-tetramethyl-1,3,7,9,-tetraazospiro[5.5]undecane-2,8-dione

{[Sc₂(C₁₁H₂₀N₄O₂)₃(H₂O)₆]⁶⁺ · 6(NO ₃ ^? )} _n (I), a coordination metallopolymer, has been synthesized for the first time and analyzed by X-ray diffraction. Crystals are tetragonal, space group P $bar 4$ 2₁ c, a = 21.9797(6) Å, c = 12.7499(6)Å, V = 6159.6(4) ų, ρ_calcd = 1.392 g/cm³, Z = 4. The scandium atom is coordinated to the three oxygen atoms of spirocarbone molecules, which are related to the basal molecules by the symmetry codes 3/2 ? y, 3/2 ? x, 1/2 + z and 3/2 ? y, 3/2 ? x, ? 1/2 + z, and also to three water molecules. The coordination number of scandium is 6. The coordination polyhedron of scandium is a slightly distorted octahedron with OScO angles within 84.70(15)°–95.86(14)° and 172.77(16)°–173.84(15)°. Nitrate anions are in the outer coordination sphere of the metal. The purity of compound I is verified via the Rietveld refinement of its X-ray powder diffraction pattern; the unit cell parameters at room temperature are a = 22.0589(6) Å, c = 12.7806(6) Å, V = 6219.0(6) ų. Lines unrelated to the major phas are not observed in the X-ray diffraction pattern. The content of the major phase is 100 ± 1%.