Conformational structure and vibrational spectra of methyl esters of simple aliphatic acids

1971 ◽  
Vol 36 (8) ◽  
pp. 3028-3032 ◽  
Author(s):  
S. Dirlikov ◽  
J. Štokr ◽  
B. Schneider
Keyword(s):  
Vibrational Spectra ◽  
Methyl Esters ◽  
Conformational Structure ◽  
Aliphatic Acids

Conformational structure of ethylene glycol dibenzoate. Vibrational and NMR spectra

1981 ◽  
Vol 46 (8) ◽  
pp. 1913-1929 ◽  
Author(s):  
Bohdan Schneider ◽  
Pavel Sedláček ◽  
Jan Štokr ◽  
Danica Doskočilová ◽  
Jan Lövy
Keyword(s):  
Ethylene Glycol ◽  
Vibrational Spectra ◽  
Nmr Spectra ◽  
Coupling Constants ◽  
Conformational Structure ◽  
Infrared And Raman Spectra ◽  
H Nmr ◽  
Liquid States ◽  
Crystalline Forms ◽  
C Nmr

It was found that three crystalline forms of ethylene glycol dibenzoate can be prepared. Infrared and Raman spectra of these three forms, as well as of the glassy and liquid states, were measured. From 3JHH coupling constants obtained by analysis of the 13C satellite band of the -CH2- group in 1H NMR spectra, and from the 3JCH coupling constants of the -CO.O.CH2- fragment obtained by analysis of the carbonyl band in 13C NMR spectra it was found that in the liquid state the -CH2-CH2- group exists predominantly in the gauche conformational structure, and the bonds C-O-C-C assume predominantly a trans orientation. The results of the analysis of NMR and vibrational spectra were used for the structural interpretation of conformationally sensitive bands in vibrational spectra of ethylene glycol dibenzoate.

scholarly journals An enhanced procedure for measuring organic acids and methyl esters in PM<sub>2.5</sub>

2015 ◽  
Vol 8 (3) ◽  
pp. 2379-2407
Author(s):  
F. Liu ◽  
F. Duan ◽  
K. He ◽  
Y. Ma ◽  
K. A. Rahn ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Organic Acids ◽  
Carboxylic Acids ◽  
Solid Phase ◽  
Methyl Esters ◽  
Aromatic Acids ◽  
Naphthalic Anhydride ◽  
Aliphatic Acids ◽  
Specificity And Sensitivity

Abstract. We have developed an enhanced analytical procedure to measure organic acids and methyl esters in fine aerosol with much greater specificity and sensitivity than previously available. This capability is important because of these species and their low concentrations, even in highly polluted atmospheres like Beijing, China. The procedure first separates the acids and esters from the other organic compounds with anion-exchange solid- phase extraction (SPE), then, quantifies them by gas chromatography coupled with mass spectrometry. This allows us to accurately quantify the C4-C11 dicarboxylic and the C8-C30 monocarboxylic acids. Then the acids are separated from the esters on an aminopropyl SPE cartridge, whose weak retention isolates and enriches the acids from esters prevents the fatty acids and dimethyl phthalate from being overestimated. The resulting correlations between the aliphatic acids and fatty acid methyl esters (FAMEs) suggest that FAMEs had sources similar to those of the carboxylic acids, or were formed by esterifying carboxylic acids, or that aliphatic acids were formed by hydrolyzing FAMEs. In all, 17 aromatic acids were identified and quantified using this procedure coupled with gas chromatography-tandem mass spectrometry, including the five polycyclic aromatic hydrocarbon (PAH) acids 2-naphthoic, biphenyl-4-carboxylic, 9-oxo-9H-fluorene-1-carboxylic, biphenyl-4,4´-dicarboxylic, and phenanthrene-1-carboxylic acid, plus 1,8-naphthalic anhydride. Correlations between the PAH-acids and the dicarboxylic and aromatic acids indicated that the first three acids and 1,8-naphthalic anhydride were mainly secondary, the last two mainly primary.

Analysis of NMR and Vibrational Spectra and Conformational Structure of Stereoisomers of 2,4,6-Trichloroheptane

2007 ◽  
Vol 16 (1) ◽  
pp. 215-228 ◽  
Author(s):  
D. Doskočilová ◽  
J. Štokr ◽  
B. Schneider ◽  
H. Pivcová ◽  
M. Kolinsky ◽  
...  
Keyword(s):  
Vibrational Spectra ◽  
Conformational Structure

Vibrational spectra, dipole moments, and conformational structure of araliphatic diacyl peroxides

1984 ◽  
Vol 40 (2) ◽  
pp. 166-170
Author(s):  
I. P. Zyat'kov ◽  
R. Shuster ◽  
A. I. Stankevich ◽  
G. A. Pitsevich
Keyword(s):  
Vibrational Spectra ◽  
Dipole Moments ◽  
Conformational Structure

scholarly journals Substrate specific hydrolysis of aromatic and aromatic-aliphatic esters in orchid tissue cultures

2014 ◽  
Vol 62 (1-2) ◽  
pp. 21-23 ◽  
Author(s):  
Agnieszka Mironowicz ◽  
Krystyna Kukułczanka ◽  
Antoni Siewiński
Keyword(s):  
Molecular Weight ◽  
Higher Plants ◽  
Methyl Esters ◽  
Chemical Compounds ◽  
Aliphatic Alcohols ◽  
Low Molecular Weight ◽  
Tissue Cultures ◽  
Aliphatic Acids ◽  
Aliphatic Esters ◽  
Hydrolysis Of

We found that tissue cultures of higher plants were able, similarly as microorganisms, to transform low-molecular-weight chemical compounds. In tissue cultures of orchids (<i>Cymbidium</i> 'Saint Pierre' and <i>Dendrobium phalaenopsis</i>) acetates of phenols and aromatic-aliphatic alcohols were hydrolyzed, whereas methyl esters of aromatic and aromatic-aliphatic acids did not undergo this reaction. Acetates of racemic aromatic-aliphatic alcohols were hydrolyzed with distinct enantiospecificity.

Vibrational spectra and conformational structure of polythiophene

1990 ◽  
Vol 52 (6) ◽  
pp. 633-637 ◽  
Author(s):  
O. S. Roshchupkina ◽  
L. M. Gol'denberg ◽  
I. V. Nazarova ◽  
V. A. Dement'ev ◽  
I. E. Davidova
Keyword(s):  
Vibrational Spectra ◽  
Conformational Structure
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