Substitution reactions of a water-soluble metalloporphyrin with azide and 1,1,3,3-tetramethyl-2-thiourea
The substitution reactions of tetrakis-(4-N-methylpyridyl)porphinecobalt (III) (Co TMpyP) with azide and with 1,1,3,3-tetramethyl-2-thiourea (TMTU) have been studied as a function of pH at 25° and an ionic strength of 0.5 M. The mechanistic pathway proposed for thiocyanate  and pyridine  is applicable to these ligands as well once allowance is made for two attacking forms of azide, N and HN . A TMTU axial substituent has about the same influence on the rate of further ligand substitution as does SCN and a much larger influence than does azide. Similar behavior between bound SCN and bound TMTU is also shown in electron-transfer reactions with Ru(NH ) - Whereas both sulfur-containing ligands enhance the rate relative to the diaquo complex, the azide complex undergoes reduction an order of magnitude more slowly than does the diaquo complex. © 1978. III - - - 2+ 3 3 3 6
Pasternack, Robert F.; Gillies, Bruce S.; and Stromsted, Julia P., "Substitution reactions of a water-soluble metalloporphyrin with azide and 1,1,3,3-tetramethyl-2-thiourea" (1978). Faculty Articles Indexed in Scopus. 2650.