6652-52-4Relevant articles and documents
Ionization Constants of 3-Substituted Propiolic Acids in Water
Laurence, Christian,Guilleme, Jean,Kirschleger, Bernard
, p. 1341 - 1343 (2007/10/02)
The pKa of ten 3-substituted propiolic acids XCCCO2H with X = OPh, Me, Ph, SiMe3, SPh, H, I, Cl, Br, and CO2Et have been measured at 25 deg C in water by a conductance method.The effect of substituents has been compared in the propiolic, acrylic, and benzoic series by means of linear free energy relationships.It is found that the Hammett and the DSP equations are less precisely obeyed in the propiolic series.Significant deviations occur for hydrogen and iodine which confirm the positive character of these groups when bound to an ethynyl group.