Synthesis and Kinetic Investigation of the Atropisomerization of meso-Tetra(2-cyanophenyl)porphine
- 1 November 1981
- journal article
- Published by Oxford University Press (OUP) in Bulletin of the Chemical Society of Japan
- Vol. 54 (11) , 3518-3521
- https://doi.org/10.1246/bcsj.54.3518
Abstract
Tetra(2-cyanophenyl)porphine (ToCNPP) has been synthesized and isolated into the four respective atropisomers. The rotation of a cyanophenyl ring about the bond to the methine carbon of the porphyrin leads to interconversion reactions among the isomers. The isomerization reactions have been studied kinetically by the separation and quantitative measurement of each isomer on thin layer chromatography plates. The results show that the free energy of activation for the hindered rotation is an average of ΔG*=110 kJ/mol at 50 °C. This is the highest barrier ever measured in similar porphyrin atropisomers. The apparent interaction between adjacent cyano groups is observed. The energy of interaction is estimated to be about 2.0 kJ per mole unit of interaction.Keywords
This publication has 17 references indexed in Scilit:
- Redox Reaction of the Central Metal Ions Coordinated to Tetra(p-sulfophenyl)porphine(TPPS). I. Photoreduction of Co(III)TPPS by Methanol and 2-PropanolBulletin of the Chemical Society of Japan, 1981
- Increased yield of a desired isomer by equilibriums displacement on binding to silica gel, applied to meso-tetrakis(o-aminophenyl)porphyrinThe Journal of Organic Chemistry, 1980
- Structure of the free-base "capped" porphyrin, 5,10,15,20-[pyrromellitoyl(tetrakis-o-oxyethoxyphenyl)]porphyrinJournal of the American Chemical Society, 1980
- Isolation of minor equilibrium components by continuous partition applied to substituted tetraphenylporphyrin atropisomersAnalytical Chemistry, 1980
- Conformational dynamics of .alpha.,.beta.,.gamma.,.delta.-tetraarylporphyrins and their dicationsThe Journal of Organic Chemistry, 1979
- Synthetic models for bis-metallo active sites. A porphyrin capped by a tetrakis(pyridine) ligand systemJournal of the American Chemical Society, 1978
- Rotation of phenyl rings in metal complexes of substituted tetraphenylporphyrinsJournal of the American Chemical Society, 1975
- Picket fence porphyrins. Synthetic models for oxygen binding hemoproteinsJournal of the American Chemical Society, 1975
- An NMR investigation of the atropisomers of -o-tolylporphinatonickel (II)Tetrahedron Letters, 1971
- Biphenyl-type atropisomerism as a probe for conformational rigidity of α,β,γ,δ-tetraarylporphines.Tetrahedron Letters, 1969