Systematic Synthesis, Isolation, and Photophysical Properties of Linear-Shaped Re(I) Oligomers and Polymers with 2-20 Units

作者：Yamamoto Youhei; Sawa Shuhei; Funada Yusuke; Morimoto Tatsuki; Falkenstrom Magnus; Miyasaka Hiroshi; Shishido Sayaka; Ozeki Tomoji; Koike Kazuhide; Ishitani Osamu^*

来源：Journal of the American Chemical Society, 2008, 130(44): 14659-14674.

DOI：10.1021/ja8044579

Systematic synthesis routes have been developed for the linear-shaped rhenium(I) oligomers and polymers bridged with bidentate phosphorus ligands, [Re(N boolean AND N)(CO)(3)-PP-{Re(N boolean AND N)(CO)(2)-PP-)(n)-Re(N boolean AND N)(CO)(3)](PF6)(n+2) (N boolean AND N = diimine, PP = bidentate phosphine, n = 0-18). These were isolated by size exclusion chromatography (SEC) and identified by H-1 NMR, IR, electrospray ionization Fourier transform mass spectrometry, analytical SEC, and elemental analysis. Crystal structures of [Re(bpy)(CO)(3)-Ph2PC equivalent to CPPh2-Re(bpy)(CO)31(PF6)2, [Re(bpy)(CO)(3)-Ph2PC equivalent to CPPh2-Re(bpy)(CO)(2)-Ph2PC equivalent to CPPh2-Re-(bpy)(CO)31(PF6)3 and [Re(bpy)(CO)(3)-Ph2PC2H4PPh2-{Re(bpy)(CO)(2)Ph2PC2H4PPh2-}(n)Re(bpy)(CO)(3)](PF6)(n+2) (bpy = 2,2'-bipyridine, n = 1, 2) were obtained, showing that they have interligand pi-pi 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 (MLCT)-M-3 excited-state of the tricarbonyl complex unit, [Re(NAN)(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 x 10(8))-(2.5 x 10(8)) 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.

• 出版日期2008-11-5