Conclusions
-
1.
It was found that protonation of H2TPP and H2TMPP by trifluoroacetic acid in benzene takes place according to the following scheme for concentrations of TFA of 10−5–10−6 mole/liter
$$H_2 P + \xrightarrow[{(K_1 )}]{{ + TFA}}H_3 P^ + \cdot A^ - \xrightarrow[{(K_2 )}]{{ + TFA}}H_4 P^{2 + } \cdot 2A^ - $$and in contrast to polar solvents, the ratio of the constants is K2/K1 > 1.
-
2.
The values of the equilibrium constants obtained indicate that H2TPP, H2TMPP, and H2TAPP are relatively convenient for determination of trace amounts (≤10−5 mole/liter) of strong Brönsted acids in nonpolar media. The selection of the type of porphyrin base is dependent on the strength and concentration of the acid.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Literature cited
S. S. Medvedev, Usp, Khim.,37, No. 11, 1923 (1968).
L. F. Borisova, é. A. Fushman, A. N. Shupik, et al., Vysokomol. Soedin.,A23, No. 9, 1984 (1981).
V. é. L'vovskii, é. A. Fushman, and F. S. D'yachkovskii, Zh. Fiz. Khim.,56, No. 8, 1864 (1982).
B. L. Grusalimskii, Vysokomol. Soedin.,A29, No. 9, 1795 (1987).
B. F. Burnham and J. J. Zuckerman, J. Am. Chem. Soc.,92, 1547 (1970).
B. D. Berezin and O. I. Koifman, Koord. Khim.,10, 1494 (1984).
J. E. Falk, Porphyrins and Metalloporphyrins, Elsevier, Amsterdam (1964), p. 27.
P. Hambright, in: Porphyrins and Metalloporphyrins, K. M. Smith (ed.), Elsevier, Amsterdam (1975), p. 223.
L. Gilleux, P. Kranz, L. Nadjo, et al., J. Chem. Soc. Perkin Trans.,2, 475 (1984).
J. B. Milne, in: The Chemistry of Nonaqueous Solvents, J. J. Lagowski (ed.), Vol. 5B, Academic Press, New York (1978).
R. J. Abraham, G. E. Hawkes, and K. M. Smith, Tetrahedron Lett., 71 (1974).
H. Ogoshi, E. Watanabe, and Z. Yosida, Tetrahedron, 32 (1973).
V. B. Sheinin and B. D. Berezin, Proceedings of the 5th All-Union Conference on the Coordination and Physical Chemistry of Porphyrins [in Russian], Ivanovo (1988).
G. P. Fulton and G. N. La Mar, J. Am. Chem. Soc.,98, 2119 (1976).
L. P. Nekrasova, R. I. Nurmukhametov, and I. O. Shapiro, Zh. Fiz. Khim.,62, No. 8, 88 (1988).
Author information
Authors and Affiliations
Additional information
Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1506–1512, July, 1989.
Rights and permissions
About this article
Cite this article
Lalayan, S.S., Fushman, é.A., Kitaigorodskii, A.N. et al. Determination of trace amounts of Brönsted acids in nonpolar media with porphyrin bases. 1. Protonation of meso-substituted porphyrins with trifluoroacetic acid in benzene. Russ Chem Bull 38, 1376–1382 (1989). https://doi.org/10.1007/BF00978422
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00978422