Structural studies of mixed-ligands copper(II) and copper(I) complexes with the rigid nitrogen ligand: bis[ N-(2,6-diisopropylphenyl)imino]acenaphthene

Abstract

The crystal structure of the rigid bidentate nitrogen ligand bis[ N-(2,6-diisopropylphenyl)imino]acenaphtene (abbr. o, o′- iPr 2C 6H 3-BIAN) and three mixed- ligand copper complexes, namely [Cu II(AcOH)( o, o′- iPr 2C 6H 3-BIAN)Cl 2] (1), [Cu II(acac)(AcOH)( o, o′- iPr 2C 6H 3-BIAN)]·(ClO 4) (2) (where AcOH=acetic acid and acac=acetylacetonate) and [Cu IBr( o, o′ -iPr 2- p-BrC 6H 2-BIAN)] 2 ( 3) are reported. In complexes 1 and 2, the coordination around the copper(II) centre is distorted square pyramidal with acetic acid molecule in the apical position. Two imine nitrogen atoms of o, o′- iPr 2C 6H 3-BIAN are occupying the basal plane together with two chloride atoms in case of 1 and two oxygen atoms (from acac ligand) in case of 2. In complex 3 the copper(I) ion is tetrahedrally surrounded by two imine nitrogen atoms of o, o′- iPr 2- p-BrC 6H 2-BIAN, and by two bridging bromide atoms. Complex formation is followed by certain structural changes inside the rigid N–N ligand. Such changes led to an increased planarity of the o, o′- iPr 2C 6H 3-BIAN backbone, and produced a nearly perpendicular angle between the naphthalene and the aromatic imine planes.