1. Aspects of investigating scrambling in the synthesis of porphyrins: different analytical methods
- Author
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Nielsen, Christian B. and Krebs, Frederik C.
- Subjects
- *
PORPHYRINS , *MACROCYCLIC compounds , *BIOLOGICAL pigments , *HETEROCYCLIC compounds - Abstract
Abstract: Herein, we discuss the analyses and quantification of the different components in porphyrin mixtures, prepared from p-anisaldehyde, p-tolualdehyde, and 5-(4-bromophenyl)-dipyrromethane with acid catalysis, using NMR and HPLC. The advantages and disadvantages of these analytical methods are emphasized. Due to the similar size of a bromine atom and a methyl group it was possible to grow crystals suitable for X-ray crystallographic studies from a mixture of porphyrins, where the 4-position of the meso-phenyl rings was either substituted with methyl groups or bromine atoms. We also show that X-ray studies are inferior to NMR analysis for determining the components in a porphyrin mixture. [Copyright &y& Elsevier]
- Published
- 2005
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