Carbonyl Stretching Frequencies of Some Partially Fluorinated Esters

• Published in: The Journal of chemical physics 1962-01, Vol.36 (6), p.1571-1573
• Main Authors: Radell, Jack, Harrah, Larry A.
• Format: Article
• Language: English
• ISSN: 0021-9606; 1089-7690
• DOI: 10.1063/1.1732781

The carbonyl stretching frequencies of 19 esters of perfluorinated normal acids and 17 esters of partially fluorinated normal alcohols were measured with a precision of 0.5 cm—1. The carbonyl stretching frequencies of the fluorinated esters were found to be consistently higher than the carbonyl stretching frequencies of the corresponding unfluorinated esters and dependent on the amount and position of the fluorine substituents. The behavior of the carbonyl stretching frequency as a function of fluorine position and number can be generalized with the following equation for the acid moiety: νc=0=ν0+15nα+4.07nβ+1.88nγ+0.8nδ,where ν0 is the carbonyl stretching frequency of the unfluorinated ester and nα, nβ, etc., are the numbers of fluorines on the α, β, etc., carbons in the acid segment. The carbonyl stretching frequencies in the esters with fluorine substitution in the alkyl segment is given by νc=0=ν0+7.97nβ′+1.78nγ′+1.83nδ′+nε′,where νc=0 has its previous significance and nβ′, nα′, etc. are the number of fluorines on the β, α etc. carbons of the alkyl chain.