Solvent-induced Changes in the Selectivity of Solvolyses in Aqueous Alcohols and Related Mixtures

Butanolysis of 2‐methylbenzenediazonium ions: product distribution, rate constants of product formation, and activation parameters

“…[51][52][53] The hypothesis of 2MBD ions mainly sampling in the interfacial region of the reverse Scheme 3. Proposed reaction mechanism for solvolysis of ArN þ 2 in binary BuOH/H 2 O mixtures showing the formation of a ion-molecule complex and a solvent separated ion-molecule pair [28,44] micelles is consistent with results in normal SDS micelles, where it has been shown by 1 H NMR experiments that the -N þ 2 group of 2MBD is located in the Stern layer. [36,54] ArN þ 2 ions have been, and still are, employed to probe interfacial compositions of weakly basic nucleophiles in a number of surfactant assemblies and, in fact, Romsted and coworkers were able to measure local nucleophile concentrations in cationic reverse micelles by combining results from hydrophobic and hydrophilic arenediazonium ions.…”

“…Kinetic and mechanistic studies in mixed solvents have an advantage in providing the opportunity to vary continuously the reaction conditions, in contrast to the more abrupt changes arising from studies of substituent effects. [1,2] Nevertheless, solubility problems may occur preventing systematic studies on individual substrates over the whole composition range. For example, short chain alkyl alcohols (C n H 2nþ1 OH, n < 3) such as MeOH or EtOH are miscible with water at any proportion but the long chain ones (n !…”

Solvolysis of Some Arenediazonium Salts in Binary EtOH/H2O Mixtures under Acidic Conditions

“…Determination of selectivity values at different solvent compositions provided evidence of the presence of cationic intermediates, complementing other studies involving addition of nucleophilic traps, which suffer from the disadvantage that they may induce mechanistic changes. [17,20,22,23] To expand the general understanding of dediazoniation mechanisms in alcoholic solvents, we have undertaken a physical organic chemistry investigation of the ethanolysis of 2-, 3-, and 4-methylbenzenediazonium ions under acidic conditions throughout the whole composition range. As a result, dediazoniation product distributions, selectivity values, rate constants for product formation and for arenediazonium ion loss, and activation parameters were determined.…”

Effect of substituents in the ring on the structure and electron density distribution in benzyl halides

“…As a result, the sum of R a and R 7 decreases, which is equivalent to a shortening of the C(7)--C1(I0) bond (see Table 1), as the electron-withdrawing ability of substituents increases in the series of compounds la--g and 2. Therefore, an increase in the electron density Pc at the critical point between the C(7) and CI (10) atoms is equivalent to a decrease in the bond length d between these atoms. The shortening of the C(7)--C1(10) bond in the series of compounds la--g and 2 is also evidenced by the increase in the order n of this bond (see Table 1).…”