Photophysics and luminescence spectroelectrochemistry of [Tc(dmpe)3](+/2+) (dmpe = 1,2-bis(dimethylphosphino)ethane)
| Autor: | Sayandev Chatterjee, Carl J. Seliskar, Samuel A. Bryan, Zheming Wang, Andrew S. Del Negro, Frances N. Smith, B. Patrick Sullivan, William R. Heineman, Sean E Hightower |
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| Rok vydání: | 2013 |
| Předmět: |
chemistry.chemical_classification
Quenching (fluorescence) chemistry.chemical_element Time-dependent density functional theory Rhenium Photochemistry Coordination complex chemistry.chemical_compound chemistry Transition metal Excited state Physical chemistry 1 2-Bis(dimethylphosphino)ethane Physical and Theoretical Chemistry Luminescence |
| Zdroj: | The journal of physical chemistry. A. 117(48) |
| ISSN: | 1520-5215 |
| Popis: | The ligand-to-metal charge transfer (LMCT) excited state luminescence of [Tc(dmpe)3](2+) (dmpe is 1,2-bis-(dimethylphosphino)ethane) has been measured in solution at room temperature and is compared to its Re analogue. Surprisingly, both [M(dmpe)3](2+)* (M = Re, Tc) species have extremely large excited-state potentials (ESPs) as oxidants, the highest for any simple coordination complex of a transition metal. Furthermore, this potential is available using a photon of visible light (calculated for M = Tc; E°'* = +2.48 V versus SCE; λmax = 585 nm). Open shell time-dependent density functional theory (TDDFT) calculations support the assignment of the lowest energy transition in both the technetium and rhenium complexes to be a doublet-doublet process that involves predominantly LMCT (dmpe-to-metal) character and is in agreement with past assignments for the Re system. As expected for highly oxidizing excited state potentials, quenching is observed for the excited states of both the rhenium and technetium complexes. Stern-Volmer analysis resulted in quenching parameters for both the rhenium and technetium complexes under identical conditions and are compared using Rehm-Weller analysis. Of particular interest is the fact that both benzene and toluene are oxidized by both the Re and Tc systems. |
| Databáze: | OpenAIRE |
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