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Isoporphycene: The Fourth Constitutional Isomer of Porphyrin with an N 4 Core—Occurrence of E / Z Isomerism
Author(s) -
Vogel Emanuel,
Scholz Peter,
Demuth Ralf,
Erben Christoph,
Bröring Martin,
Schmickler Hans,
Lex Johann,
Hohlneicher Georg,
Bremm Dominik,
Wu YunDong
Publication year - 1999
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/(sici)1521-3773(19991004)38:19<2919::aid-anie2919>3.0.co;2-w
Subject(s) - porphyrin , chemistry , derivative (finance) , cis–trans isomerism , ligand (biochemistry) , stereochemistry , core (optical fiber) , catalysis , structural isomer , photochemistry , organic chemistry , materials science , biochemistry , receptor , financial economics , economics , composite material
Liberation of the ligand from the nickel complex 1 obtained by template synthesis yielded isoporphycene (as the octaethyl derivative 2 ), the first constitutional isomer of porphyrin with an N 4 core for which E / Z isomerism is involved: Compound 2 is present as the E isomer, which is in rapid, presumably acid‐catalyzed equilibrium with a small amount (2 %) of the Z isomer. The remaining unknown constitutional isomers of porphyrin are considerably higher in energy than the already rather labile isoporphycene, so that the latter should mark the border of existence for this type of structural variant of porphyrin.