Synthesis And Properties Of Metal-tetrahydroxymethyl-tetra-(1,4-dithiin)-porphyrazine

Increasingly aggravated water pollution has posed a major threat to survival security of life-form and been a major obstacle to human health, economic and social sustainable development. It is very urgent to protect water resources. As biomimetic photocatalyst applied in the treatment of pollutants, porphyrin and phthalocyanine have attracted considerable attention in recent years. Heterogenous photocatalytic oxidation technology utilizing solar energy is almost non-selectivity to organic pollutants, mineralization thoroughly and energy conservation. Hence, it has good prospects for the development and application.Iron(II) tetra(1,4-dithiin)-porphyrazine (abbreviated as FePz(dtn)4) has a closely fused macrocyclic skeleton with an extended delocalized 18Ï€-electron conjugated macrocyclic system. Its photocatalytic performance is better than iron- phthalocyanines. The FePz(dtn)4 can activate and catalyze H2O2 and O2 to degrade the organic pollutants. In order to improve the lipophilic and hydrophilic capability, we succeeded in introducing hydroxymethyl groups onto the periphery of tetra- (1,4-dithiin)-porphyrazine and changing the central metal iron for manganese, copper ann zinc to form four novel complexes. Furthermore, their capability for degrading the organic pollutants in heterogeneous photocatalytic system was studied and the satisfying experimental results were gained.There are three parts to be included in this paper:1. Four novel metal tetrahydroxymethyl-tetra(1,4-dithiin)-porphyrazine MPz(HOCH2-dtn)4 (M=Fe, Mn, Cu and Zn) have been synthesized according to the template method using 2,3-dicyano-5-hydroxymethyl-1,4-dithiin as thire precursor.2. The physical and chemical properties of the four transition metal complexes were investigated. The result indicated that the lipo-solubility was improved after introducing hydroxymethyl onto the periphery of tetra-(1,4-dithiin)-porphyrazine and their physical properties were changed.3. Based on Rhodamine B(RhB) as the model molecular of degradation, the photocatalytic property of four metal complexes were studied initially under mild conditions. The results showed that the better capacity for activation of dioxygen and peroxide hydrogen was displayed by not only the FePz(HOCH₂-dtn)₄ but also other three of complexes MPz(HOCH₂-dtn)₄ (M= Mn, Cu and Zn), all of them can degrade RhB in water under irradiation of visible light effectively.