The synthesis and investigation of different cobaloximines by spectroscopic methods

Abstract

In the present work, firstly a novel monoxime (1) and unsymmetric dioxime ligand (LH2) (2) derived from 4-(4-hydroxyphenyl)-2-butanone as ketone was prepared under optimum conditions. Then, the cobaloxime complexes [(LH)2ClCoB] (B = neutral base: 4-DAP = 4-(dimethylamino)pyridine, 4-HP = 4-hydroxypyridine, 4-CP = 4-chloropyridine, 4-MP = 4-methylpyridine, 4-EP = 4-ethylpyridine, 4-TBP = 4-tert-butylpyridine and P = pyridine) (3–9) with respect to varied axial groups were synthesized in a two-necked round-bottom reaction flask by direct contact of dioxime ligand (2), and different neutral base without special requirement of any additional chemical process. The prepared dioxime ligand (2) and its cobaloxime complexes (3–9) were characterized by means of NMR, FT-IR, UV–Vis and LC-MS spectroscopy, melting point and magnetic susceptibility measurements as well as elemental analysis. It is noteworthy that the coordination chemistry of this cobaloxime complexes is versatile, which is closely related to the nature of the unsymmetric dioxime ligand (2) derived from 4-(4-hydroxyphenyl)-2-butanone, as indicated by the results of the corresponding spectroscopic studies. Also, the spectroscopic results demonstrated that the proposed cobaloxime complexes are a six-coordinated species and octahedral geometry.