S. Funahashi, Motoharu Tanaka
1984
Citations
0
Influential Citations
46
Citations
Journal
Bulletin of the Chemical Society of Japan
Abstract
The kinetics of reactions of 5,10,15,20-tetraphenylporphine (H2(tpp)) and N-methyl-5,10,15,20-tetraphenylporphine (H(metpp)) with CuII, ZnII, and CdII ions was studied spectrophotometrically in N,N-dimethylformamide. The rate of incorporation of metal ions (M2+ : Cu2+, Zn2+, Cd2+) into H(metpp) is first order with respect to both H(metpp) and metal ion: d[M(metpp)+]/dt=[k[H(metpp)][M2+] with k(25 °C)=11.5±0.5 mol−1 dm3 s−1 for Zn2+ and (5.8±0.8)×102 mol−1 dm3 s−1 for Cd2+. The rate of incorporation of copper and zinc into H2(tpp) is first order in H2(tpp) and the conditional first-order rate constants are expressed as follows: k0(M)=K[M2+](1+K[M2+])−1(k1+k2[M2+]) where for Cu2+ and Zn2+ K/mol−1 dm3, k1/s−1, and k2/mol−1dm3 s−1 at 25°C are (1.6±0.2)×104 and (7.2±1.5)×102, (1.2±0.1)×10−4 and (3.5±0.7)×10−5, and (5.2±0.2)×10−2 and (8.6±0.2)×10−4, respectively. Metal ion incorporation into H2(tpp) proceeds through the formation of intermediates prior the rate-limiting step. For the H(metpp) system, the methyl...