A Study of the Dipolar Spin System in Selectively Deuterated Nematogens

Autor: E. Tomchuk, J. J. Visintainer, B. Nakka, Ronald Y. Dong, E. Bock
Rok vydání: 1977
Předmět:
Zdroj: Molecular Crystals and Liquid Crystals. 38:53-59
ISSN: 0026-8941
Popis: The proton spin dipolar relaxation times and dipolar echo responses were studied for the nematic phase of ring-deuterated p-methoxybenzylidene-p-n-butylaniline (MBBA-d) as a function of temperature and frequency. Measurements of the proton dipolar echo responses were also made for methyl-deuterated p-azoxyanisole (PAA-d6). The echo response was used to determine the inter-pair second moment M2 (inter), while the total second moment M2 was extracted from the echo shape. Both of these second moments were determined for the ring protons in PAA-d6 and the end chain protons in MBBA-d8 and are discussed in terms of the averaging caused by the internal motions of the molecules. The dipolar relaxation times measured for the side chain protons in MBBA-d8 indicate a lower “effective” viscosity for this part of the molecule.
Databáze: OpenAIRE