Dimerization in trans-4-butyl-cyclohexane carboxylic acid and in its mixture with 12% cis-isomer observed via 1H- and 2H-NMR

Sofia I. Torgova; D. Abramic; Alfredo Strigazzi; Slobodan Zumer

doi:10.1117/12.301319

1 January 1998 Dimerization in trans-4-butyl-cyclohexane carboxylic acid and in its mixture with 12% cis-isomer observed via ¹H- and ²H-NMR

Sofia I. Torgova, D. Abramic, Alfredo Strigazzi, Slobodan Zumer

Author Affiliations +

Proceedings Volume 3319, Liquid Crystals: Chemistry and Structure; (1998) https://doi.org/10.1117/12.301319
Event: Liquid Crystals, 1997, Zakopane, Poland

Abstract

In this paper we report the investigation, performed via proton- and deuteron-NMR on samples of trans-4-butyl- cyclohexane carboxylic acid (C₄), and via proton-NMR on samples of a cis-trans mixture of the same substance, containing 12 percent cis-isomer (C_4.12). The aim of the research was to study the dimerization process at different temperatures via NMR technique. As it is known, only the presence of a conveniently large proportion of closed dimers of trans-isomer allows the nematic mesophase to be established. The results obtained with proton-NMR on C₄, approaching on cooling the clearing point, revealed, as expected, the increasing of the amount of closed dimers. Just below the clearing point, in a range of a couple degrees only, the presence of open dimers was detected. On the contrary, down into the nematic phase, only closed dimers turned out to be present. The results obtained via deuteron-NMR on C₄, deuterated in the hydroxy position, are consistent with the proton-NMR data. Moreover, the deuteration was found to strongly influence the bonding energy, thus forcing the nematic phase to appear at definitely lower temperature. Furthermore, proton-NMR investigation of C_4.12 samples showed a clearing interval instead of a clearing point. These results suggest a phase separation, which is in agreement with our microscopy observations. The presence of open dimers in a small temperature range, just below the clearing interval, is also confirmed. But we didn't succeed to obtain any information about mixed dimers.

Citation Download Citation

Sofia I. Torgova, D. Abramic, Alfredo Strigazzi, and Slobodan Zumer "Dimerization in trans-4-butyl-cyclohexane carboxylic acid and in its mixture with 12% cis-isomer observed via ¹H- and ²H-NMR", Proc. SPIE 3319, Liquid Crystals: Chemistry and Structure, (1 January 1998); https://doi.org/10.1117/12.301319

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
7 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Hydrogen

Temperature metrology

Molecules

Microscopy

Chemical analysis

Infrared spectroscopy

Liquid crystals

Show All Keywords

Keywords/Phrases

Search In:

Publication Years