Revisited Photophysics and Photochemistry of a Ru-TAP Complex Using Chloride Ions and a Calix[6]crypturea
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- 作者：Mateusz Rebarz ; Lionel Marc茅lis ; Micka毛l Menand ; Damien Cornut ; C茅cile Moucheron ; Ivan Jabin ; Andr茅e Kirsch-De Mesmaeker
- 刊名：Inorganic Chemistry
- 出版年：2014
- 出版时间：March 3, 2014
- 年：2014
- 卷：53
- 期：5
- 页码：2635-2644
- 全文大小：516K
- 年卷期：v.53,no.5(March 3, 2014)
- ISSN：1520-510X
文摘
The effects of the nonprotonated and protonated calix[6]crypturea 1/1鈥?/sup>H+ on the PF6鈥?/sup> and Cl鈥?/sup> salts of a luminescent Ru-TAP complex (TAP = 1,4,5,8-tetraazaphenanthrene) were investigated. Thus, the phototriggered basic properties of this complex were examined with 1鈥?/sup>H+ in acetonitrile (MeCN) and butyronitrile (BuCN). The Ru excited complex was shown to be able to extract a proton from the protonated calixarene, accompanied by a luminescence quenching in both solvents. However, in BuCN, the Cl鈥?/sup> salt of the complex exhibited a surprising behavior in the presence of 1/1鈥?/sup>H+. Although an emission decrease was observed with the protonated calixarene, an emission increase was evidenced in the presence of nonprotonated 1. As the Cl鈥?/sup> ions were shown to inhibit the luminescence of the complex in BuCN, this luminescence increase by nonprotonated 1 was attributed to the protection effect of 1 by encapsulation of the Cl鈥?/sup> anions into the tris-urea binding site. The study of the luminescence lifetimes of the Ru-TAP complex in BuCN as a function of temperature for the PF6鈥?/sup> and Cl鈥?/sup> salts in the absence and presence of 1 led to the following conclusions. In BuCN, in contrast to MeCN, in addition to ion pairing, because of the poor solvation of the ions, the luminescent metal-to-ligand charge transfer (3MLCT) state could reach two metal-centered (3MC) states, one of which is in equilibrium with the 3MLCT state during the emission lifetime. The reaction of Cl鈥?/sup> with this latter 3MC state would be responsible for the luminescence quenching, in agreement with the formation of photosubstitution products.