Systematic Synthesis, Isolation, and Photophysical Properties of Linear-Shaped Re(I) Oligomers and Polymers with 2−20 Units
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- 作者：Youhei Yamamoto ; Shuhei Sawa ; Yusuke Funada ; Tatsuki Morimoto ; Magnus Falkenströ ; m ; Hiroshi Miyasaka ; Sayaka Shishido ; Tomoji Ozeki ; Kazuhide Koike ; Osamu Ishitani
- 刊名：Journal of the American Chemical Society
- 出版年：2008
- 出版时间：November 5, 2008
- 年：2008
- 卷：130
- 期：44
- 页码：14659-14674
- 全文大小：696K
- 年卷期：v.130,no.44(November 5, 2008)
- ISSN：1520-5126
文摘
Systematic synthesis routes have been developed for the linear-shaped rhenium(I) oligomers and polymers bridged with bidentate phosphorus ligands, [Re(N^N)(CO)3-PP-{Re(N^N)(CO)2-PP-}nRe(N^N)(CO)3](PF6)n+2 (N^N = diimine, PP = bidentate phosphine, n = 0−18). These were isolated by size exclusion chromatography (SEC) and identified by 1H NMR, IR, electrospray ionization Fourier transform mass spectrometry, analytical SEC, and elemental analysis. Crystal structures of [Re(bpy)(CO)3-Ph2PCCPPh2-Re(bpy)(CO)3](PF6)2, [Re(bpy)(CO)3-Ph2PCCPPh2-Re(bpy)(CO)2-Ph2PCCPPh2-Re(bpy)(CO)3](PF6)3 and [Re(bpy)(CO)3-Ph2PC2H4PPh2-{Re(bpy)(CO)2Ph2PC2H4PPh2-}nRe(bpy)(CO)3](PF6)n+2 (bpy = 2,2′-bipyridine, n = 1, 2) were obtained, showing that they have interligand π−π interaction between the bpy ligand and the phenyl groups on the phosphorus ligand. All of the oligomers and polymers synthesized were emissive at room temperature in solution. For the dimers, broad emission was observed with a maximum at 523−545 nm, from the 3MLCT excited-state of the tricarbonyl complex unit, [Re(N^N)(CO)3-PP-]. Emission from the longer oligomers and polymers with ≥3 Re(I) units was observed at wavelengths 50−60 nm longer than those of the corresponding dimers. This fact and the emission decay results clearly show that energy transfer from the edge unit to the interior unit occurs with a rate constant of (0.9 × 108)−(2.5 × 108) s−1. The efficient energy transfer and the smaller exclusive volume of the longer Re(I) polymers indicated intermolecular aggregation for these polymers in an MeCN solution.