Synthesis of 21,23-Selenium- and Tellurium-Substituted 5‑Porphomethenes, 5,10-Porphodimethenes, 5,15-Porphodimethenes, and Porphotrimethenes and Their Interactions with Mercury
journal contributionposted on 17.04.2015, 00:00 by Sohail Ahmad, Kumar Karitkey Yadav, Soumee Bhattacharya, Prashant Chauhan, S. M. S. Chauhan
The 3+1 condensation of symmetrical 16-Selena/telluratripyrranes with symmetrical selenophene-2,5-diols/tellurophene-2,5-diols in the presence of BF3-etheratre or BF3-methanol followed by oxidation with DDQ gave 5,10-porphodimethenes, whereas the process with unsymmetrical selenophene-2,5-diols/tellurophene-2,5-diols gave 5-porphomethenes. In addition, the reaction of unsymmetrical 16-Selena/telluratripyrranes with symmetrical selenophene-2,5-diols/tellurophene-2,5-diols gave the corresponding porphotrimethenes, whereas the process with unsymmetrical selenophene-2,5-diols/tellurophene-2,5-diols gave the 5,15-porphodimethenes. The structures of different products were characterized by IR, 1H and 13C NMR, 1H–1H COSY, CHN analysis, and mass spectrometry. The binding of mercury with the calixphyrins mentioned above had been observed in the decreasing order of porphodimethenes > porphomethenes > porphotrimethenes by UV–vis and 1H NMR spectroscopy.