Vibrational spectroscopic study on polymorphism of erucic acid and palmitoleic acid: γ1→α1 and γ→α reversible solid state phase transitions

Kaneko, Fumitoshi; Yamazaki, Kazuhiro; Kobayashi, Masamichi; Sato, Kiyotaka; Suzuki, Masao

doi:10.1016/0584-8539(94)e0069-m

Cited by 22 publications

(22 citation statements)

References 22 publications

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“…The weak band at 856 cm -1 is proposed to be characteristic of the O-O linkage in hydroperoxides, even though its lack of intensity limits its usefulness [15]. The band at 721 cm -1 , similar to the one observed in the spectrum of fatty acids and triglycerides, could be assigned to the CH 2 rocking mode [9]. Assignment of vibrations to the weak bands at low frequencies is difficult and somewhat tentative; still, the bands at 577 and 518 cm -1 could be assigned as C-H out of plane bending [7,16].…”

Section: Resultsmentioning

confidence: 66%

“…The band at 2999 cm -1 , similar to the one observed at 3006 cm -1 in the infrared spectrum of oleic acid [8], could be the CH stretching related to =C-H bonding, or a combination band (= 1651+1342 cm -1 ). C-H asymmetric and symmetric stretching vibrations, representing aliphatic CH 2 , could be attributed to the very strong band at 2911 cm -1 (the corresponding Raman frequency also at 2911 cm -1 ) and its doublet at 2842 cm -1 , respectively [6], while CH 2 scissors deformation vibration [9,10] could be assigned to the medium strong one at 1460 cm -1 (the corresponding Raman peak appearing at 1450 cm -1 ). C=O stretching vibration of the carboxylic groups (methyl esters and triglycerides) could be attributed [11] to the very strong band at 1746 cm -1 .…”

Section: Resultsmentioning

confidence: 99%

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Spectroscopic Investigation of the Cashew Nut Kernel (Anacardium occidentale)

Barua¹,

Hazarika²,

Hussain³

et al. 2008

TOFSJ

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Fourier transform infrared and Fourier transform Raman spectra of the kernel of the cashew nut (Anacardium occidentale) are presented. Based on the correlations with the infrared spectra of its individual components and other compounds already published, assignments of the observed bands have been done. The infrared spectrum is shown to be very similar to that of triolein, a triglyceride of oleic acid a characteristic useful in reducing the low-density lipoprotein (LDL) cholesterol level of the person consuming it.

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Section: Resultsmentioning

confidence: 66%

Section: Resultsmentioning

confidence: 99%

Spectroscopic Investigation of the Cashew Nut Kernel (Anacardium occidentale)

Barua¹,

Hazarika²,

Hussain³

et al. 2008

TOFSJ

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“…In the solid state, the olefinic hydrogen bend region shows complex behavior (34), but since the preferred method would be to measure liquid samples (to reduce complications associated with the carbonyl internal standard), this is unlikely to constitute a serious problem.…”

Section: Resultsmentioning

confidence: 99%

A critical evaluation of Raman spectroscopy for the analysis of lipids: Fatty acid methyl esters

Beattie

Bell

Moss³

2004

Lipids

116

126

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The work presented here is aimed at determining the potential and limitations of Raman spectroscopy for fat analysis by carrying out a systematic investigation of C4-C24 FAME. These provide a simple, well-characterized set of compounds in which the effect of making incremental changes can be studied over a wide range of chain lengths and degrees of unsaturation. The effect of temperature on the spectra was investigated over much larger ranges than would normally be encountered in real analytical measurements. It was found that for liquid FAME the best internal standard band was the carbonyl stretching vibration v(C=O), whose position is affected by changes in sample chain length and physical state; in the samples studied here, it was found to lie between 1729 and 1748 cm(-1). Further, molar unsaturation could be correlated with the ratio of the nu(C=O) to either nu(C=C) or delta(H-C=) with R2 > 0.995. Chain length was correlated with the delta(CH2)tw/v(C=O) ratio, (where "tw" indicates twisting) but separate plots for odd- and even-numbered carbon chains were necessary to obtain R2 > 0.99 for liquid samples. Combining the odd- and even-numbered carbon chain data in a single plot reduced the correlation to R2 = 0.94-0.96, depending on the band ratios used. For molal unsaturation the band ratio that correlated linearly with unsaturation (R2 > 0.99) was nu(C=C)/delta(CH2)sc (where "sc" indicates scissoring). Other band ratios show much more complex behavior with changes in chemical and physical structure. This complex behavior results from the fact that the bands do not arise from simple vibrations of small, discrete regions of the molecules but are due to complex motions of large sections of the FAME so that making incremental changes in structure does not necessarily lead to simple incremental changes in spectra.

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“…In previous works we investigated the structural change of each transition by means of vibrational spectroscopy and clarified that the higher temperature phases, R and R1, contained conformational disorders in the vicinity of the methyl terminals while the carboxyl-terminal chains kept all-trans conformation. 12,13 So we concluded that both these transitions are of the order f disorder type. Such a partial melting process at lamellar surfaces has not been found in other long-chain compounds consisting of saturated acyl chains.…”

Section: Introductionmentioning

confidence: 92%

Mechanism of the γ → α and γ1 → α1 Reversible Solid-State Phase Transitions of Erucic Acid

Kaneko¹,

Yamazaki²,

Kobayashi³

et al. 1996

J. Phys. Chem.

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Two reversible solid-state phase transitions of erucic acid (cis-13-docosenoic acid), the γ f R and γ1 f R1 phase transitions, have been followed by vibrational spectroscopy (IR and Raman) and X-ray diffraction. The crystal structure analyses of the higher temperature phases, R and R1, have been performed. The symmetry of crystal lattices remains unchanged during the both transitions, i.e., the γ and R phases belong to a monoclinic system (P2 1 /a) and the γ1 and R1 phases belong to a triclinic one (P1 h). At the γ f R transition point, the subcell structure of the methyl-terminal chains is reconstructed, accompanying a large conformational change of cis-olefin groups. On the γ1 f R1 transition, the inclination manner of hydrocarbon chains changes, while there are no significant changes in the subcell structure and the conformation of cis-olefin groups. The conformational disorder at methyl terminals increases continuously for the γ1 f R1 transition, contrary to an abrupt occurrence at the γ f R transition. The unit cell volume also increases gradually in the γ1 and R1 phases and shows no prominent changes at the γ1 f R1 transition, while a stepwise increase takes place at the γ f R transition. The important factors for transition behaviors are discussed on the basis of the crystal structures.

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Vibrational spectroscopic study on polymorphism of erucic acid and palmitoleic acid: γ1→α1 and γ→α reversible solid state phase transitions

Cited by 22 publications

References 22 publications

Spectroscopic Investigation of the Cashew Nut Kernel (Anacardium occidentale)

Spectroscopic Investigation of the Cashew Nut Kernel (Anacardium occidentale)

A critical evaluation of Raman spectroscopy for the analysis of lipids: Fatty acid methyl esters

Mechanism of the γ → α and γ1 → α1 Reversible Solid-State Phase Transitions of Erucic Acid

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