Tetrabenzoporphyrins: metal incorporation and exchange kinetics, ligational equilibria and pulse radiolysis studies

✍ Scribed by S. Cromer; P. Hambright; J. Grodkowski; P. Neta

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 182 KB
• Volume: 01
• Category: Article
• ISSN: 1088-4246
• DOI: 10.1002/(sici)1099-1409(199701)1:1<45::aid-jpp3>3.0.co;2-d

✦ Synopsis

The solution chemistry of tetrabenzoporphyrin (TBP) and several of its metal derivatives were compared with that of the corresponding octaethylporphyrins. Kinetic studies were done on zinc and cadmium ion incorporation and the exchange reactions of cadmium porphyrins with zinc. Formation constants of Cd(II), Cu(II), VO(IV), Ni(II), Zn(II) and Mg(II) porphyrins with pyridine were determined for both compounds. The spectra of the radical cations of Ni(II), Mg(II) and H 2 -TBP were obtained, as well as that of the radical anion of Mg(II)-TBP. Aside from the new Ni(I)-TBP, no long-lived intermediates, as noted with other porphyrins, were observed upon reduction of the tetrabenzoporphyrins. The low basicity and rigidity of the tetrabenzoporphyrin nucleus may explain many of its relative reactivity properties.