Coordination diversity of copper(II) phosphoryl-functionalized salicylaldiminates: Effect of the length of the pendant phosphoryl arm

The reaction of copper acetate with phosphoryl-substituted salicylaldimines 2a,b and template assembling of the imines on different sources of the copper(II) ion have been studied. The length of the pendant phosphoryl arm and reaction conditions were found to strongly affect the reaction course, selectively resulting in four- (3), five- (4, 6), or six-coordinate (5) Cu(II) complexes. In the case of the derivatives with the elongated phosphoryl arm, the product structure is dictated by the nature of a solvent system used for recrystallization. In the case of the derivatives with the P O group directly attached to the central benzene ring, the reaction result depends on the nature of the reagents. An unusual example of a mixed aldehydate–iminate complex (compound 6) has been detected that can be used to obtain unsymmetrical bis(iminate) complexes (e.g., compound 7). The structures of all the complexes obtained were unambiguously confirmed based on the IR spectral data as well as single-crystal and powder X-ray diffraction.