Synthesis, characterization, DFT studies, and immobilization of cobalt(II) complex with N,N′,N″-tris(2-pyrimidinyl)dimethylentriamine on modified iron oxide as oxidation catalyst

[Co3(PDMT)Cl6] complex, in which PDMT is N,N′,N″-tris(2-pyrimidinyl)dimethylentriamine was prepared in cyclohexanol under hydrothermal condition. At first, the crystal structure of PDMT was solved based on the Rietveld method by using laboratory X-ray powder diffraction data. The molecular geometry of the ligand and complex were optimized by B3LYP method. In order to heterogenize the prepared complex, it was immobilized on the modified Fe3O4 nanoparticles with (3-aminopropyl)trimethoxysilane (APTMS). The prepared compound designated as Fe3O4@SiO2-2@APTMS@[Co3(PDMT)Cl6] was found to successfully catalyze the epoxidation of cyclooctene, styrene, cyclohexene, trans-stilbene as well as oxidation of fluorene, diphenylmethane, ethylbenzene, adamantane, cyclohexane, cyclooctane and norbornene with TBHP as oxidant with 25–100% conversions and 18–100% selectivities. Ligand, complex and Fe3O4@SiO2-2@APTMS@[Co3(PDMT)Cl6] were characterized by FT-IR, TEM, XRD, Mass, UV–Vis, DSC-TGA, NMR, GC and GC–Mass techniques.

Graphical abstract[Co3(PDMT)Cl6] complex, in which PDMT is N,N′,N″-tris(2-pyrimidinyl)dimethylentriamine was prepared. Crystal structure of PDMT was solved based on the Rietveld method. The molecular geometry of the ligand and complex were optimized by B3LYP method. It was then immobilized on the modified Fe3O4 nanoparticles in order to use as oxidation catalyst.Figure optionsDownload full-size imageDownload as PowerPoint slide