A porphyrin derivative with highly red shifted and intensified absorption bands immobilized into the mesopores of nanostructured amberlite: Synthesis, characterization and photocatalytic activity

Abstract

The BF3 complex of meso-tetra(4-sulfonatophenyl)porphyrin (H2TPPS4), immobilized into the pores of a new nano-structured mesoporous anion exchange polymer, nanoAmbN(Me)3Cl (Amb = Amberlite IRA-410(Cl)) was used as the photosensitizer for aerobic oxidation of organic compounds. NanoAmbN(Me)3Cl, nanoAmbN(Me)3@H2TPPS4 and nanoAmbN(Me)3@H2TPPS4(BF3)2, were characterized by IR and UV–vis diffuse reflectance spectroscopy (UV–vis DRS) methods, TGA, FESEM, elemental mapping (SEM-EDX) and BET. The nanocomposite was used as photosensitizer in the aerobic oxidation of 1,5-dihydroxynaphthalene (DHN) and cyclohexene in acetonitrile. The results were compared with those obtained in the presence of the BF3 complex of meso-tetrakis(N-methylpyridinium-4-yl)porphyrin (H2TMPyP) immobilized on nanostructured amberlyst 15. The observed red shifts in the UV–vis DRS UV–vis spectrum upon the formation of nanoAmbN(Me)3@H2TPPS4(BF3)2 were much larger than those of nanoAmbSO3@H2TMPyP(BF3)2. The singlet quatum yield of nanoAmbN(Me)3@H2TPPS4 and nanoAmbN(Me)3@H2TPPS4(BF3)2 was determined by using 1,3-diphenylisobenzofuran (DPBF) and DHN as the quenchers of singlet oxygen, for the excitation of the photosensitizers in the Q and Soret band regions, respectively.