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8688106 
Journal Article 
Infrared Study of Methylene Group Absorptivities in Polar Straight Chain Aliphatic Compounds 
Zenker, W 
1972 
Yes 
Analytical Chemistry
ISSN: 0003-2700
EISSN: 1520-6882 
44 
7 
1235-1239 
English 
A new experimental method, based on compensation, is introduced which corrects for the mutual overlap of methyl and methylene bands in the asymmetrical C-H stretching region, enabling accurate measurements of methyl and methylene peak intensities. The absorption bands are actually recorded individually using cyclohexane and hexamethyldisilazane as compensating agents. Values for the methylene group absorptivities in homologous series of n-alkanes, n-alcohols, n-aldehydes, and n-carboxylic acids, weee obtained without lengthy procedures by simply using the ratio of methylene/methyl peak absorbances. A function relating the experimental data is derived and discussed. It is shown that the methylene group absorptivity decreases with increasing polarity of the functional group and that the influence of a polar group is still evident twenty methylene groups away from the functional group. 1972, American Chemical Society. All rights reserved.