Mixed-ligand copper(II) complexes with N-isopropyl-iminodiacetato(2-) and C-phenyl-imidazole ligands.: Crystal structures of H2iPIDA, [Cu(iPIDA)(H2φim)(H2O]•3H2O and [Cu(iPIDA)(H5φim)]n

The crystal of the N-isopropyl-iminodiacetic acid (1) consists of a 3D H-bonded framework where the zwitterion (H(2)iPIDA(+/-)) is intra-stabilized by one N+-(HO)-O-... interaction and both carboxyl are half-protonated and involved in linear O-(HO)-O-... inter-molecular bridges of 2.46 angstrom. The mixed-ligand complexes [Cu(iPIDA)(H2 phi im)(H2O)](.)3H(2)O (2) and [Cu(iPIDA)(H5 phi](n) (3) have also been synthesized and studied by thermal, spectral, magnetic and X-ray diffraction methods, Both complexes exhibit a square base pyramidal coordination, type 4+1. Compound 3 is the less steric hindered 'remote' isomer, with H5 phi im instead of H4 phi im.