期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1971
卷号：68
期号：6
页码：1289-1293
DOI：10.1073/pnas.68.6.1289
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The ring orientation in {beta}-ionone, all-trans retinal, and 11-cis retinal, relative to that of the polyene chain, has been determined by means of semi-empirical calculations and magnetic resonance measurements of the nuclear Overhauser effect and long-range coupling constants. The experimental results yield a distorted s-cis conformation about the C6-C7 "single bond", with the torsional angle in the range 30{degrees} to 70{degrees}. This agrees well with the semi-empirical potential function, which has a broad, rather flat minimum for angles from 40{degrees} to 120{degrees}. The temperature dependence of the NMR results provide confirmation for the form of the torsional potential.
