A square-pyramidal copper(II) complex with strong intra­molecular hydrogen bonds: diaqua­(N,N′-di­methyl­formamide-κO)bis­[2-(diphenyl­phosphor­yl)benzoato-κO]copper(II)

In the title Cu^II complex, [Cu(C₁₉H₁₄O₃P)₂(C₃H₇NO)(H₂O)₂], the mol­ecule is bis­ected by a twofold axis relating the two 2-(di­phenyl­phosphor­yl)benzoate (ODPPB) ligands. The asym­­metric unit consists of a Cu^II metal centre on the sym­metry axis, an ODPPB ligand, one water ligand and one dimethyl­formamide (DMF) ligand (disordered around the twofold axis). The Cu^II ion has fivefold coordination provided by two carboxyl­ate O atoms from two ODPPB ligands, two O atoms from two coordinated water mol­ecules and another O atom from a (disordered) DMF mol­ecule, giving a CuO₅ square-pyramidal coordination geometry. The ODPPB ligand adopts a terminal monocoordinated mode with two free O atoms forming two strong intra­molecular hydrogen bonds with the coordinated water mol­ecules, which may play a key role in the stability of the mol­ecular structure, as shown by the higher release temperature for the coordinated water mol­ecules than for the coordinated DMF mol­ecule. The optical absorption properties of powder samples of the title compound have also been studied.