Outer-Sphere 2 e

Autor: Mauricio, Cattaneo, Scott A, Ryken, James M, Mayer
Rok vydání: 2016
Předmět:
Zdroj: Angewandte Chemie (International ed. in English). 56(13)
ISSN: 1521-3773
Popis: A diverse set of 2e−/2H+ reactions are described that interconvert [RuII(bpy)(en*)2]2+ and [RuIV(bpy)(en-H*)2]2+ (bpy = 2,2’-bipyridine, en* = H2NCMe2CMe2NH2, en*-H = H2NCMe2CMe2NH−), forming or cleaving different O-H, N-H, S-H and C-H bonds. The reactions involve quinones, hydrazines, thiols and 1,3-cyclohexadiene. These proton-coupled electron transfer (PCET) reactions occur without substrate binding to the ruthenium center, but with precursor complex formation by hydrogen bonding. The free energies of the reactions vary over more than 90 kcal mol−1, but the rates vary more with the kind of X–H bond involved than with this ∆G°. There is a kinetic preference for substrates that have the transferring H’s in close proximity, such as ortho-tetrachlorobenzoquinone over its para isomer and 1,3-cyclohexadiene over its 1,4-isomer, perhaps hinting at the potential for concerted 2e−/2H+ transfers.
Databáze: OpenAIRE