Orientational ordering of 4-substituted phenylcyclohexanes studied by carbon-13 two-dimensional N.M.R.
作者:
CherylBaldwin Frech,
B.M. Fung,
Martin Schadt,
期刊:
Liquid Crystals
(Taylor Available online 1988)
卷期:
Volume 3,
issue 6-7
页码: 713-722
ISSN:0267-8292
年代: 1988
DOI:10.1080/02678298808086526
出版商: Taylor & Francis Group
数据来源: Taylor
摘要:
An N.M.R. method combining the techniques of separated local field spectroscopy (SLF) and variable angle spinning (VAS) is valuable in the investigtion of nematic liquid crystals. Rapid sample spinning causes the nematic director to align along the spinning axis, resulting in narrow peaks in the C-13 N.M.R. spectrum. SLF is a two-dimensional N.M.R. method which produces a first order splitting pattern for each carbon signal from which C–H dipolar coupling constants can be determined. The order parameters for all segments of the liquid crystal molecule can then be calculated. Results for three 4′-cyanophenylcyclohexanes are considered here. These compounds are trans-substituted at the 4 position of cyclohexane ring withn-pentane (PCH5), 1-pentene (3d1CP) and 3-pentene (1d3CP), respectively.
点击下载:
PDF (560KB)
返 回