Two-dimensional NMR investigations of the dynamic conformations of phospholipids and liquid crystals
- Univ. of California, Berkeley, CA (United States). Applied Science and Technology
Two-dimensional 13C, 1H, and 31P nuclear magnetic resonance (NMR) techniques are developed and used to study molecular structure and dynamics in liquid-crystalline systems, primarily phospholipids and nematic liquid crystals. NMR spectroscopy characterizes molecular conformation in terms of orientations and distances of molecular segments. In anisotropically mobile systems, this is achieved by measuring motionally-averaged nuclear dipolar couplings and chemical shift anisotropies. The short-range couplings yield useful bond order parameters, while the long-range interactions constrain the overall conformation. In this work, techniques for probing proton dipolar local fields are further developed to obtain highlyresolved dipolar couplings between protons and rare spins. By exploiting variable-angle sample spinning techniques, orientation-sensitive NMR spectra are resolved according to sitespecific isotropic chemical shifts. Moreover, the signs and magnitudes of various short-range dipolar couplings are obtained. They are used in novel theoretical analyses that provide information about segmental orientations and their distributions. Such information is obtained in a model-independent fashion or with physically reasonable assumptions. The structural investigation of phospholipids is focused on the dynam
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 6429
- Report Number(s):
- LBNL-42162; TRN: US200305%%724
- Resource Relation:
- Other Information: TH: Thesis (Ph.D.); Supercedes report DE00006429; Submitted to the Univ. of California, Dept. of Chemistry, Berkeley, CA (US); PBD: 28 May 1996; PBD: 28 May 1996
- Country of Publication:
- United States
- Language:
- English
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