ORGN 143 |
| Amide to carboxylic acid hydrogen bonds are rare but found in natural products such as bilirubin. Bilirubin IXa is a unique linear tetrapyrrole produced in the body as the end product of heme degradation. The shape of bilirubin IXa plays an important role on the chemo-physical properties, making it very interesting to study. Bilirubin IXa can participate in intramolecular hydrogen bonding, which causes it to adopt a ridge-tile shape. To study the relationship between hydrogen bonding and 3-dimentional shape, models for bilirubin have been synthesized. An attractive model for one-half of bilirubin is composed of a dipyrrole unit with an attached alkanoic chain able to participate in intramolecular hydrogen bonding. With acid, ester and amide functional groups attached to the end of the alkyl chain one may study the competitive intra and inter- molecular hydrogen bonding. In order to sort out intra and inter-molecular hydrogen bonding in semirubin dipyrrinones with various amides attached to the end of the alkyl chain, the series is studied by UV-vis spectroscopy (Beers law), 1H NMR spectroscopy (NOE) and vapor pressure osmometry (VPO). |
|
Heterocycles, Aromatics, Materials, Devices, Switches, Combinatorial Chemistry, Metal-Mediated Reactions
8:00 PM-10:00 PM, Sunday, 13 March 2005 Convention Center -- Hall D, Poster
Division of Organic Chemistry |