Synthesis, X-ray structural and thermal analysis of a novel copper compound containing dissymmetric independent 5- and 6-coordinate CuL(H2O)n (n=2,3) units and hydrogen bond bridges

Abstract

The synthesis, thermogravimetric and X-ray structure analysis of a highly unusual copper compound prepared from a chiral tridentate Schiff base ligand is reported. The title compound [CuC₁₆H₁₉NO₇][CuC₁₆H₁₇NO₆].H₂O crystallizes in the orthorhombic crystal system in space group P2₁2₁2₁ with Z = 4. Two independent CuL(H₂O)_x complexes are present in the same unit cell, one five- and the other six- coordinate. The five-coordinate copper(II) centre occupies a distorted square-pyramidal geometry whereas the six-coordinate copper(II) centre has a distorted octahedral geometry. The independent copper complexes and the uncoordinated water molecule are joined together with intermolecular hydrogen bonds in a two-dimensional supramolecular network which lies parallel to the ab plane.