Synthesis of meso-tetraarylthienylporphyrins by Suzuki-Miyaura cross-coupling reaction and studying their UV-Vis absorption spectra

Abstract

meso-Tetra(5-arylthien-2-yl)porphyrins and their copper complexes were synthesized by two different approaches using Suzuki-Miyaura cross-coupling reactions. The first, involving the formation of 5-arylthien-2-yl carbaldehydes, followed by condensation with pyrrole. The second is a direct process that involves the coupling of meso-tetra (5-bromothien-2-yl) porphyrins with the arylboronic acids. The yield of the second approach (40-50 %) was higher than the first approach (28-35 %). The UV-Vis absorption spectra of the synthesized porphyrins revealed bathochromic shifts when compared with the parent porphyrin. Additionally, the products showed no aggregation behaviour in solution (DCM), giving a linear correlation between absorption intensity and the concentration.