Preparation And Catalytic Performance Of Terpyridine Pd,Fe Complexes Self-Assembly Films

In this paper, 4’-(4-Carboxyphenyl)-2,2’:6’,2"-terpyridine was synthesized. The Self-assembly films of terpyridine Pd, Fe complexes(Si-Pd, Si-Fe) were prepared on hydrophilic substrates using bottom-up approach and characterized by water contact angle(WCA), atomic force microscopy(AFM), UV-vis spectrophotometry(UV),X-ray photoelectron spectrum(XPS) and cyclic voltammetry(CV); The Suzuki coupling reactions was selected as model for evaluating the catalytic properties of self-assembled monolayer of Si-Pd;The synthesis of benzimidazole compounds was selected as template for evaluating the catalytic ability of self-assembled monolayer of Si-Fe, and the catalytic mechanism was investigated preliminarily. The main contents are listed as follow:1. The self-assembly films of terpyridine Pd, Fe Complexes(Si-Pd, Si-Fe) were prepared on hydrophilic substrates using bottom-up approach(Scheme 1).2. The Suzuki coupling reactions was selected as model for evaluating the catalytic properties of self-assembled monolayer of Si-Pd. Under the optimized condition, the self-assembled monolayer of Si-Pd showed high catalytic efficiency with turnover number reaching up to 1.11 × 104. Research on the mechanism of Suzuki coupling reaction showed that the palladium on surface of the self assembled monolayer really played a great role in reaction process, and palladium species leaching into the reaction solution was not detected. Therefore, it was proved that the catalytic reaction was indeed heterogeneous, which occurred on the surface of the self-assembled monolayer substrate.3. The synthesis of benzimidazole compounds was selected as template for evaluating the catalytic ability of the self-assembled monolayer of Si-Fe. Under the optimized condition, the self-assembled monolayer of Si-Fe showed high catalytic efficiency with turnover number reaching up to 2.2×104 while displaying good tolerance to functional groups. Moreover, the catalyst was also recycled up to 10 times without any significant loss of activity(Figure 1).The mechanism of synthesis of benzimidazoles from aromatic diamines and aldehydes was studied preliminarily.First, schiff base was formed by dehydration of o-phenylendiamine, then, a five-membered ring was produced via ring closure, and dehydrogenation with the self-assembled monolayer of Si-Fe to form benzimidazole.