ISSN:
0006-3525
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The side chain conformations of α-helical poly(L-glutamic acid) esters \documentclass{article}\pagestyle{empty}\begin{document}$ \rlap{--}[NHCH(CH_2 CH_2 COOR)CO\rlap{--}]_x $\end{document}, carrying a homologous series of ester residues such as R = —(CH2)nφ with n = 1-3, have been studied in the lyotropic liquid crystalline state (chloroform 20 v/v%) by the deuterium nmr method. In order to study the surface chirality of the molecule, the phenyl groups situated at the terminal of the side chain have been deuterated. From the observed deuterium quadrupolar splittings, the average inclination θp of the para-axis of the phenyl group with respect to the α-helical backbone was elucidated. A distinct odd-even oscillation in the quantity such as 〈 cos2 θp〉 was observed with the number of methylene units n. A rotational isomeric state analysis has indicated that the observed orientational correlation arises from the interdependence of the neighboring bond rotation along the side chain. Preference of the “extended” conformations is also enhanced by the mutual conformational exclusion of neighboring side chains.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bip.360281112
