QUANTITATIVE STUDY OF THE DISSOCIATION OF DIMERIC CIS-9, CIS-12-OCTADECADIENOIC ACID IN PURE LIQUID BY THE FT-IR LIQUID-FILM TECHNIQUE

被引:14
作者
CZARNECKI, MA
OZAKI, Y
SUZUKI, M
IWAHASHI, M
机构
[1] KWANSEI GAKUIN UNIV,SCH SCI,DEPT CHEM,NISHINOMIYA,HYOGO 662,JAPAN
[2] KITASATO UNIV,SCH HYG SCI,DEPT CHEM,SAGAMIHARA,KANAGAWA 228,JAPAN
[3] NIPPON OIL & FATS CO LTD,AMAGASAKI 660,JAPAN
关键词
FT-IR; ANALYTICAL METHODS; CIS-9; CIS-12-OCTADECADIENOIC ACID; FATTY ACIDS; THERMODYNAMIC PARAMETERS; HYDROGEN BONDING;
D O I
10.1366/0003702934066398
中图分类号
TH7 [仪器、仪表];
学科分类号
0804 ; 080401 ; 081102 ;
摘要
The study of the infrared spectra of neat cis-9, cis-12-octadecadienoic acid in the liquid phase has been carried out over a temperature range of 31 to 110-degrees-C. In the region of 1710 cm-1 a strong absorption band accompanied by two weaker bands appears. The strong band is assigned to a C=O stretching vibration due to the dimeric form of the acid, and the weaker bands near 1750 and 1650 cm-1 are attributed to a C=O stretching vibration due to its monomer and to C=C stretching modes arising from both forms, respectively. The shape of the band envelope strongly depends on temperature. Making a curve fitting, one can determine spectral parameters of the individual bands, and from them it is possible to calculate the degree of dissociation of the acid. The obtained values of the degree of dissociation enable us to determine enthalpy (DELTAH) and entropy (DELTAS) for the process of dissociation of dimeric species into free molecules, and the results seem to be reasonable as compared with the literature data for other fatty acids.
引用
收藏
页码:2157 / 2161
页数:5
相关论文
共 21 条
[1]  
GARTI N, 1988, CRYSTALIZATION POLYM
[2]  
GRIFFITHS PR, 1987, COMPUTER ENHANCED AN
[3]  
HAMILTON RJ, 1987, RECENT ADV CHEM TECH
[4]   MEASUREMENT OF CONFORMATIONAL EQUILIBRIA VIA INFRARED - STUDIES OF 1,1-DIBROMO-3-FLUOROBUTADIENE-1,3 AND 1,1-DICHLORO-3-FLUOROBUTADIENE-1,3 [J].
HARTMAN, KO ;
CARLSON, GL ;
WITKOWSK.RE ;
FATELEY, WG .
SPECTROCHIMICA ACTA PART A-MOLECULAR SPECTROSCOPY, 1968, A 24 (02) :157-&
[5]  
HAUSER H, 1985, CHIMIA, V39, P252
[6]   INFRARED SPECTROSCOPIC EVIDENCE FOR COEXISTENCE OF 2 MOLECULAR CONFIGURATIONS IN CRYSTALLINE FATTY-ACIDS [J].
HAYASHI, S ;
UMEMURA, J .
JOURNAL OF CHEMICAL PHYSICS, 1975, 63 (05) :1732-1740
[7]   INTERPRETATION FOR THE ANOMALY OF THE C=O STRETCHING BAND IN BENZOIC-ACID CRYSTAL [J].
HAYASHI, S ;
OOBATAKE, M ;
NAKAMURA, R ;
MACHIDA, K .
JOURNAL OF CHEMICAL PHYSICS, 1991, 94 (06) :4446-4452
[8]   TEMPERATURE-DEPENDENCE OF MOLECULAR-CONFORMATION AND LIQUID STRUCTURE OF CIS-9-OCTADECENOIC ACID [J].
IWAHASHI, M ;
YAMAGUCHI, Y ;
KATO, T ;
HORIUCHI, T ;
SAKURAI, I ;
SUZUKI, M .
JOURNAL OF PHYSICAL CHEMISTRY, 1991, 95 (01) :445-451
[9]  
IWAHASHI M, COMMUNICATION
[10]   VIBRATIONAL SPECTROSCOPIC STUDY ON POLYMORPHISM AND ORDER-DISORDER PHASE-TRANSITION IN OLEIC-ACID [J].
KOBAYASHI, M ;
KANEKO, F ;
SATO, K ;
SUZUKI, M .
JOURNAL OF PHYSICAL CHEMISTRY, 1986, 90 (23) :6371-6378