Countercations and Solvent Influence CO2 Reduction to Oxalate by Chalcogen-Bridged Tricopper Cyclophanates
| Autor: | Gianna N. Di Francesco, Khalil A. Abboud, Leslie J. Murray, Brian J. Cook |
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| Rok vydání: | 2018 |
| Předmět: |
Tris
010405 organic chemistry Chemistry chemistry.chemical_element General Chemistry 010402 general chemistry 01 natural sciences Biochemistry Medicinal chemistry Copper Catalysis Oxalate 0104 chemical sciences Solvent chemistry.chemical_compound Chalcogen Colloid and Surface Chemistry Yield (chemistry) Cyclophane |
| Zdroj: | Journal of the American Chemical Society. 140:5696-5700 |
| ISSN: | 1520-5126 0002-7863 |
| DOI: | 10.1021/jacs.8b02508 |
| Popis: | One-electron reduction of Cu3EL (L3– = tris(β-diketiminate)cyclophane, and E = S, Se) affords [Cu3EL]−, which reacts with CO2 to yield exclusively C2O42– (95% yield, TON = 24) and regenerate Cu3EL. Stopped-flow UV/visible data support an A→B mechanism under pseudo-first-order conditions (kobs, 298K = 115(2) s–1), which is 106 larger than those for reported copper complexes. The kobs values are dependent on the countercation and solvent (e.g., kobs is greater for [K(18-crown-6)]+ vs (Ph3P)2N+, and there is a 20-fold decrease in kobs in THF vs DMF). Our results suggest a mechanism in which cations and solvent influence the stability of the transition state. |
| Databáze: | OpenAIRE |
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