Synthesis, structural analysis and evaluation of the catalytic activity of a non-symmetric N-(salicylidene)diethylenetriamine complex of copper(II)

A new copper(II) complex of a non-symmetric Schiff base, [CuII(saldien)(H2O)]+ (1), has been synthesized and characterized by elemental analysis and several other spectroscopic methods (Hsaldien = N-(salicylidene)diethylenetriamine). The crystal structure of 1 has also been determined by X-ray crystallography. The geometry of the complex cation in 1 was found to be distorted square pyramidal with the mononegative Schiff base coordinating to the copper in a tetradentate mode via the O,N,N', and N”-donor atoms. The remaining coordination site was occupied by the O atom of a H2O molecule in the axial position. The catalytic potential of 1 was tested in the oxidation reactions of cyclooctene and cyclohexene with aqueous 30% H2O2/NaHCO3 in acetonitrile. These reactions proceeded smoothly to give the corresponding epoxides with selectivity levels greater than 99%. This catalytic system also showed high levels of activity and selectivity towards the oxidation of cyclohexane (i.e., cyclohexanol 37% and cyclohexanone 54%) in comparison with most of the other Cu-based systems reported in the literature.

Synthesis and crystal structural analysis of a new copper(II) complex of a non-symmetric Schiff base have been reported. The complex showed high levels of catalytic activity and selectivity towards the oxidation of cycloalkenes and cyclohexane by H2O2 and NaHCO3.Figure optionsDownload as PowerPoint slide