ISSN:
0377-0486
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
Resonance Raman spectra, obtained with 5145, 4880 and 3638 Å excitation, are reported for aquo-, methyl-, 5′-deoxyadenosyl-(coenzyme B12), thiosulfate and cysteinyl cobalamin, of methyl cobinamide, and of Co(II) cobalamin (B12r). Laser-induced photodecomposition was held to acceptable levels with a rapid-flow technique. A rich assortment of corrin ring vibrations are observed above 600 cm-1, but the frequencies are constant (within ±3 cm-1) for all the derivatives. Some Raman bands show differential enhancement by the visible and near-ultraviolet electronic transitions, reflecting their different polarizations. B12r shows large relative intensity changes in bands at 1500 and 1600 cm-1, with respect to the Co(III) derivatives. Despite an absorption spectrum resembling that of B12r, methyl cobinamide shows Raman intensity behavior typical of the other Co(III) derivatives.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jrs.1250060202
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