Effect of solvents and counterions on the equilibrium and kinetics of disproportionation of tetracenide radical ions

Reactions of cation radicals of EE systems. 10. The influence of ion association on cation radical disproportionation

“…solvent. 19 Several spectroscopic characterizations of ion pairing processes involving cation radicals similar to those examined in this work have recently been reported. Sorensen and Bruning20 examined electron-transfer kinetics of phenothiazine cation radical in acetonitrile-chloroform mixtures.…”

“…Szwarc and co-workers have shown that both the equilibrium position and the kinetics of anion radical disproportionation can be markedly altered by aggregation of the anionic forms of the substrate with various alkali metal cations. [16][17][18][19] In the case of tetracene anion radical, for example, the disproportionation equilibrium constant was caused to vary over some seventeen orders of magnitude by appropriate choice of cation and. solvent.…”

Photoinduced electron transfer of carbanions and carbocations

“…An early report [36] of the photochemistry of COT-2 in the presence of weak acids such as amines and terminal alkynes showed that it is protonated in the excited state (to give the monoanion): COT -2 is more basic in the excited state than in the ground state. However, in the absence of such weak adds, photolysis of COT -2 results in electron photoejection [37][38][39]. The electron photoejection process and subsequent chemistry has been studied in solution [37], in a glass [38] and on semiconductor electrodes using COT -2 derivatives [38].…”

“…However, in the absence of such weak adds, photolysis of COT -2 results in electron photoejection [37][38][39]. The electron photoejection process and subsequent chemistry has been studied in solution [37], in a glass [38] and on semiconductor electrodes using COT -2 derivatives [38]. Scheme 7 depicts the reaction scheme for photolysis of 19 [40,41].…”

“…Scheme 7 depicts the reaction scheme for photolysis of 19 [40,41]. [37] have studied the kinetics of the disproportionation reaction of 20 with different cations in several solvents. The anion 20 was photogenerated by flash photolysis.…”