Polarized Spectra of Oriented Films of Raman a-Helical and its Poly(L-alanine) N-Deuterated Analogue
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چکیده
Polarized Raman spectra were obtained on well oriented Ðlms of a-helical poly(L-alanine) (a-PLA) and its Ndeuterated analogue in order to obtain deÐnitive assignments of the modes. Such assignments were aided E 2 -species by an analysis of factors that can lead to “cross-talkÏ between A, and spectra, viz. reÑection of the incident E 1 E 2 beam and non-perfect lateral and axial chain orientation in the sample. The convincing assignment of at least eleven signiÐcant modes in a-PLA has led to the reÐnement of a new empirical force Ðeld and a more detailed E 2 normal mode analysis. 1998 John Wiley & Sons, Ltd. (
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