Crystal structure of four rare-earth (La, Nd, Er, Lu) complexes with di(hydroxymethyl)phosphinic acid

X-ray diffraction of four rare earth (RE) compounds LaL3 (1), NdL3 (2), ErL3 · H2O (3) and LuL3 (4), HL - di(hydroxymethyl)phosphinic acid (HOCH2)2PO(OH) is conducted. Crystals of 1, 2 complexes are isostructural. Central atom of RE is associated with four phosphine atoms of oxygen O(P) of six ligands L in structures of the 1 - 4 compounds. Coordination of metal atoms in the 1 and 2 is added to distorted dodecahedron (6 O(P) + 2 O(C)) by two hydroxy atoms of two ligands L. Coordination polyhedron of Er atom in the 3 structure is defined as a disordered pentagonal bipyramid (6 O(P) + O(C), coordination polyhedron of Lu atom in the 4 structure - almost normal octahedron (6 O(P)). RE atom in the 1 - 4 structure is associated with six ligands L to produce a layered structure. Layers in the 3 are combined by hydrogen bonds with the participation of crystallization water. The ligands L are acting as bidentate μ2-bridge function (2 O(P) in the 1 - 4 structures; one independent ligand - in the 1, 2 structures, two ligands - in the 3 structure, all three ligands - in the 4 structure), or tridentate chelate-μ2-bridge function (2 O(P) + O(C); two ligands - in the 1, 2 structures, one ligand - in the 3 structure)