Crystal structure of the mixed-ligand copper(II) complex with S-proline-N-monoacetate dianion and imidazole [Cu(Proma)(Im)] · H2O

Abstract

The crystal structure of the [Cu(Proma)(Im)] · H2O coordination compound (where Proma2− is an S-proline-N-monoacetate dianion and Im is imidazole) is studied by X-ray diffraction. The crystals are orthorhombic, a = 8.286 A, b = 8.546 A, c = 17.309 A, Z = 4, and space group P212121. The structural units of the crystal are the [Cu(Proma)(Im)] molecular complexes and crystallization water molecules. The square coordination of the Cu atom involves O atoms of two acetate groups (Cu-O, 1.958 and 1.955 A) and N atoms of the Proma and Im ligands (Cu-N, 1.986 and 1.958 A). The terminal O atoms of the neighboring complexes complete the Cu coordination polyhedron to a 4 + 1 + 1 square bipyramid (Cu-O, 2.578 and 2.783 A) and form a framework structure. The hydrogen bonds involving oxygen atoms of the Proma ligand, water molecules, and an uncoordinated nitrogen atom of the Im ligand contribute to the strengthening of the framework.