Abstract Second-order rate constants () have been measured spectrophotometrically for nucleophilic substitution reactions of 4-nitrophenyl X-substituted-cinnamates (7a-7e) and Y- substituted-phenyl cinnamates (8a-8e) with butane-2, 3-dione monoximate () in 80 mol%/20 mol% DMSO at. The Hammett plot for the reactions of 7a-7e consists of two intersecting straight lines while the Yukawa-Tsuno plot exhibits an excellent linearity with= 0.85 and r= ...
