Anisotropic molecular reorientation of hexafluorobenzene in binary liquid mixtures with benzene and cyclohexane. A nuclear magnetic relaxation study

✍ Scribed by Martin A. Suhm; Hermann Weingärtner

• Publisher: Elsevier Science
• Year: 1989
• Tongue: English
• Weight: 570 KB
• Volume: 159
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(89)87408-1

✦ Synopsis

times T, of hexanuorobenzene in binary liquid mixtures with benzene and cyclohexane at 25 "C were studied at resonance frequencies of 19.5 and 83 MHz. The data indicate a frequency dependence of T, caused by relaxation through chemical shift anisotropy, enabling the correlation time 7L for the tumbling motion of C6F6 to be determined. Combination with correlation times 7, for the in-plane motion derived from '"C relaxation times makes it possible to extract information on the anisotropic reorientation of CsF6. Reorientation of C6F6 in the pure liquid is markedly anisotropic, with 7L/7ll ~2.7. Dilution in benzene increases the reorientational anisotropy, while dilution in cyclohexane produces no change.