ISSN:
0006-3525
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Laser Raman spectra are reported for solid films cast from a series of solutions containing mixtures of right- and left-handed α-helices of poly-γ-benzyl-L- and D-glutamate. Procedures were established for producing spectra that were reproducible in position to ±0.3 cm-1 and in relative intensity to a few percent for features of interest. Spectra for the pure L and pure D polymers were identical, as expected. Several small but definite spectral changes appear in the mixtures, reaching a maximum for the racemic 50:50 mixture. The changes are a shift of -1.4 cm-1 in the amide I peak at 1650.5 cm-1; a shift of about -5 cm-1 in the partially resolved amide III peak at 1291 cm-1; a shift of +2.5 cm-1 in the benzyl peak at 3062.5 cm-1; changes in relative intensity of as much as 50% in several regions; and the marked enhancement of several peaks, particularly that at 254 cm-1. These changes are discussed in terms of side-chain interactions in the packing of right- and left-handed helices.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bip.1974.360130714
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