| Autor: |
Pascual-Leone N; Department of Chemistry , Amherst College , Merrill Science Building , Amherst , Massachusetts 01002 , United States., Conklin E; Department of Chemistry , Amherst College , Merrill Science Building , Amherst , Massachusetts 01002 , United States., Andrade GA; Department of Chemistry and Biochemistry, Brown Laboratory , University of Delaware , Newark , Delaware 19716 , United States., Rosenthal J; Department of Chemistry and Biochemistry, Brown Laboratory , University of Delaware , Newark , Delaware 19716 , United States., Young ER; Department of Chemistry , Lehigh University , Seeley G. Mudd , Bethlehem , Pennsylvania 18015 , United States. |
| Jazyk: |
angličtina |
| Zdroj: |
The journal of physical chemistry. A [J Phys Chem A] 2019 Sep 12; Vol. 123 (36), pp. 7673-7682. Date of Electronic Publication: 2019 Sep 04. |
| DOI: |
10.1021/acs.jpca.9b04427 |
| Abstrakt: |
Excited states of tris(2,2'-bipyridine)ruthenium(II), [Ru(bpy) 3 ] 2+ , can be deactivated by a wide range of ferrocene derivatives. The pathway by which deactivation takes place, either energy transfer (EnT) or electron transfer (ET), depends on several factors inherent to each specific donor-acceptor (D···A) system. In this work, we provide mechanistic insight into bimolecular quenching between [Ru(bpy) 3 ] 2+* and several ferrocene (Fc) derivatives in a variety of solvents. By introducing various functional groups onto the cyclopentadienyl ring of ferrocene, the chemical properties of the organometallic complexes were altered by tuning the oxidation potentials and charge of the iron complexes, and the manner in which the [Ru(bpy) 3 ] 2+ excited state is quenched by each ferrocene complex in solvents of various dielectric constants, including anhydrous acetonitrile (ACN), dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and water (pH 10), was assessed. Through the use of transient absorption (TA) spectroscopy, the mechanism of [Ru(bpy) 3 ] 2+* quenching by each of five ferrocene derivatives (i.e., either EnT or ET) in the aforementioned solvents was evaluated. On the basis of these studies, electrostatic factors relating to the charge on the ferrocene moiety were found to influence the quenching pathway(s) for the [Ru(bpy) 3 ] 2+ ···Fc systems under interrogation. When the ferrocene moiety is positively charged, the [Ru(bpy) 3 ] 2+ excited state is quenched by EnT to Fc, while when the ferrocene moiety is neutral or negatively charged, the [Ru(bpy) 3 ] 2+ excited state is quenched via reductive ET. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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