Photobehavior of (-Diimine)dimesitylplatinum(II) Complexes
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- 作者：Keenan E. Dungey ; Brian D. Thompson ; Noel A. P. Kane-Maguire ; and Laura L. Wright
- 刊名：Inorganic Chemistry
- 出版年：2000
- 出版时间：November 13, 2000
- 年：2000
- 卷：39
- 期：23
- 页码：5192 - 5196
- 全文大小：62K
- 年卷期：v.39,no.23(November 13, 2000)
- ISSN：1520-510X
文摘
The photobehavior of complexes of the type Pt(diimine)(mes)2 is investigated (where diimine = 2,2'-bipyridine(bpy), 1,10-phenanthroline (phen), 3,4,7,8-tetramethyl-1,10-phenanthroline (tmp), 2,9-dimethyl-1,10-phenanthroline(2,9-dmp), 5,6-dimethyl-1,10-phenanthroline (5,6-dmp), and 4,7-diphenyl-1,10-phenanthroline (dpp) and mes =the mesityl (2,4,6-trimethylphenyl) anion). For all compounds studied, solution RT emission is observed to beweak and excited-state lifetimes are found to be short (
20 ns) regardless of solvent choice. Evidence is presentedfor energy-transfer quenching of Pt(dpp)(mes)2 luminescence in toluene by dissolved O2 (primarily producingsinglet oxygen) with an observed quenching rate constant of kq 
1.3 × 109 M-1 s-1. Electron-transfer quenchingis also observed in the presence of 3,5-dinitrobenzonitrile, yielding a quenching rate constant of kq 1.6 × 109M-1 s-1. The latter observation suggests that these Pt(II) systems may have future value as excited-state reductants.All of the complexes display a much more intense and longer-lived luminescence in the solid state at roomtemperature. Several possible explanations for this dependence on phase are proposed, with the most probablemechanism involving radiationless deactivation in solution via rotation of the o-methyl groups of the mesitylligands.
20 ns) regardless of solvent choice. Evidence is presentedfor energy-transfer quenching of Pt(dpp)(mes)2 luminescence in toluene by dissolved O2 (primarily producingsinglet oxygen) with an observed quenching rate constant of kq 1.3 × 109 M-1 s-1. Electron-transfer quenchingis also observed in the presence of 3,5-dinitrobenzonitrile, yielding a quenching rate constant of kq 1.6 × 109M-1 s-1. The latter observation suggests that these Pt(II) systems may have future value as excited-state reductants.All of the complexes display a much more intense and longer-lived luminescence in the solid state at roomtemperature. Several possible explanations for this dependence on phase are proposed, with the most probablemechanism involving radiationless deactivation in solution via rotation of the o-methyl groups of the mesitylligands.