ORGN 534 |
| Dipyrrinones are the component chromophores of the tetrapyrrole bilirubin IXa, the end product of heme degradation. Dipyrrinones are interesting compounds due to a hydrogen bonding motif that is available for either intra or inter-molecular hydrogen bonding. Bilirubin is able to utilize the hydrogen bonding capability of the dipyrrinone units via the attached carboxylic acid groups and form intramolecular hydrogen bonds. Such intramolecular hydrogen bonds enable bilirubin to adopt a ridge-tile shape and cause the molecule to be unexpectedly lipophilic. Dipyrrinones in non-polar solvents are dimeric, forming four intermolecular hydrogen bonds. Tethering two dipyrrinones covalently with a long diacyl chain restricts intermolecular hydrogen bonding. Stereochemical and hydrogen bonding analyses are presented from 1H NMR, NOE experiments, UV-vis spectroscopy, VPO measurements and X-ray crystallography.
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Heterocycles, Aromatics, Metal-Mediated Reactions and Syntheses, Materials, Devices, and Switches
8:00 PM-10:00 PM, Wednesday, 29 March 2006 Georgia World Congress Center -- Ex. Hall B4, Poster
Division of Organic Chemistry |