Abstract
Controlled nitration ofmeso-tetraphenylporphyrinatocopper(II) using fuming nitric acid leads to the formation of different β-substituted nitro derivatives. Five isomers of dinitro and three isomers of trinitrotetraphenylporphyrins have been isolated and characterised using FAB/MS,1H NMR, UV-VIS and IR spectroscopies. The single crystal X-ray data on the copper(II) derivative of one of the isomers of trinitrotetraphenylporphyrin revealed ‘saddle’ conformation of the porphyrin core resulting from the nitro group substitution at theβ-pyrrole carbons. The electrochemical redox behaviour of the free-base porphyrins and their copper(II) derivatives revealed that successive substitution of nitro groups at the pyrrole carbons shifts the one-electron ring oxidations anodically while the ring reduction occurs at a less cathodic potential relative to the unsubstituted porphyrin. The isomer specific shifts in the redox potentials bear a direct relationship with the relative energy levels of HOMO/LUMO obtained from AM1 calculations.
Similar content being viewed by others
References
Medforth C J, Senge M O, Smith K M, Sparks L D and Shelnutt J 1992J. Am. Chem. Soc. 114 9859
Bhyrappa P and Krishnan V 1991Inorg. Chem. 30 239
Rao S and Krishnan V 1994J. Mol. Struct. 327 279
Tsuchiya S 1991J. Chem. Soc., Chem. Commun. 716
Dahal S, Nethaji M and Krishnan V 1994Acta Crystallogr. C50 314
Dahal S and Krishnan V 1995J. Photochem. Photobiol. A: Chem. 89 105
Bartoli J F, Battioni P, De Foor W R and Mansuy D 1994J. Chem. Soc., Chem. Commun. 23
Baldwin J E, Crossley M J and Debernardis 1982Tetrahedron 39 685
Catalano M M, Crossley M J, Harding M M and King L C 1984J. Chem. Soc., Chem. Commun. 1533
Hombrecher H K, Gherdan V M, Ohm S, Cavaleiro J A S, Neves M G P M S and Condesso M F 1993Tetrahedron 49 8569
Vicente M G H, Neves M G P M S, Cavaleiro J A S, Hombrecher H K and Koll D 1996)Tetrahedron Lett. 37 261
Alder O D, Longo F R, Kampas F and Kim J 1970J. Inorg. Nucl. Chem. 32 2443
D’Souza F and Krishnan V 1990Inorg. Chim. Acta 176 131
Sheldrick G M 1985SHELXS86: Program for the solution of crystal structure, Univ. of Gottingen, Germany
Sheldrick G M 1993SHELXL93, Program for the refinement of crystal structures, Univ. of Gottingen, Germany
Crossley M J, Field L D, Harding M M and Sternhell S 1987J. Am. Chem. Soc. 109 2335
Dahal S and Krishnan V 1997Chem. Phys. Lett. 274 390
Gouterman M J 1959Chem. Phys. 30 1139
Kadish K M 1986Prog. Inorg. Chem. 34 435
Senge MO 1992J. Photochem. Photobiol. B: Biol 16 3
Barkigia K M, Berber M D, Fajer J, Medforth C J, Renner M W and Smith K M 1990J. Am. Chem. Soc. 112 8851
Anderson O D, Kapelaue A B and Lavallee D K 1980Inorg. Chem. 19 2101
Giraudeau A, Callot H J, Jordan J, Ezhar I and Gross M 1979J. Am. Chem. Soc. 101 3857
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Dahal, S., Krishnan, V. & Nethaji, M. Isomers of β-substituted di and tri-nitrotetraphenylporphyrins and their copper(II) derivatives: Structure, optical and electrochemical redox properties. Proc. Indian Acad. Sci. (Chem. Sci.) 110, 37–52 (1998). https://doi.org/10.1007/BF02871908
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1007/BF02871908