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Gas‐phase acidities of acrolein and methyl acrylate
Author(s) -
Bernasconi Claude F.,
Stronach Michael W.,
Depuy Charles H.,
Gronert Scott
Publication year - 1990
Publication title -
journal of physical organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.325
H-Index - 66
eISSN - 1099-1395
pISSN - 0894-3230
DOI - 10.1002/poc.610030512
Subject(s) - chemistry , acrolein , methyl acrylate , double bond , propionaldehyde , acrylate , medicinal chemistry , crotonaldehyde , organic chemistry , catalysis , aldehyde , copolymer , polymer
Gas‐phase acidities of acrolein and methyl acrylate were measured by bracketing in a flowing afterglow/SIFT apparatus. For acrolein Δ G ° acid = 369 ± 4 kcal mol −1 and for methyl acrylate Δ G ° acid = 373 ± 4 kcal mol −1 . These acidities are substantially lower than those of the saturated analogs propionaldehyde and methyl acetate, respectively, even though hydrogens attached to sp 2 ‐hybridized carbon are intrinsically more acidic than those attached to sp 3 ‐hybridized carbon. Resonance stabilization of the neutral form by conjugation of the CC double bond with the carbonyl group and allenic destabilization of the anionic form of the two acids can account for the relatively low acidities.