Crystal and molecular structure of [NN′-ethylenebis(salicylideneiminato)](methanol)dioxouranium

Abstract

The crystal and molecular structure of the title compound has been determined by three-dimensional X-ray methods. Crystals are monoclinic, space group P2₁/n with cell dimensions: a= 18·695(15), b= 9·012(9), c= 10·652(10)Å, γ= 97·52°(5), and Z= 4. The structure was solved by the heavy-atom method from 2239 reflections collected by counter, and refined by least-squares methods to R 0·055.

Four atoms of the Schiff base and the oxygen of the methanol are co-ordinated in a plane, forming a slightly irregular pentagon, with the uranyl group perpendicular to this plane. Equatorial U–O(3) and U–O(4) distances are 2·25(2) and 2·33(3)Å, while U–O(MeOH) is 2·45(3)Å U–N(1) and U–N(2) are 2·57(2) and 2·54(5)Å. The only short intermolecular distance, O(4)⋯ O(5) of two neighbouring molecules 2·58Å, suggests the presence of a hydrogen bond. The N(1)–CH₂–CH₂–N(2) group is in a near-gauche conformation (torsion angle 51·8°) and the complex exhibits an overall ‘stepped’ geometry. The stereochemistry and chemical properties of 3dtransition-metal compounds of such ligands are compared.