| 摘要: | 本篇論文以Bppb (1,3-bis((3-(pyridin-2-yl)-1H-pyrazol-1-yl)methyl)benzene) 或BppEb (1,2-bis(2-(3-(pyridin-2-yl)-1H-pyrazol-1-yl)ethyl)benzene) 為主結構，錸金屬為配位中心，合成一系列預期與陰離子可產生具陰離子-π作用之錸金屬錯合物，Bppb-Re-R與BppEb-Re-R (R = Br, Ph (4-phenylpyridine), L1 (2-hexyl-7-pyridin-4-yl-benzo[lmn][3,8]phenanthroline-1,3,6,8-tetraone)。
在Bppb系列，Bppb-Re-Ph與Bppb-Re-L1的1H NMR圖譜顯示最靠近吡啶的碳上氫有兩組訊號 (δ = 9.39與9.34 ppm)，表示有兩種結構。利用雙層溶劑擴散法 (acetone/hexane) 得到黃色晶體Bppb-Re-Ph。單晶結構為U型，1H NMR訊號在δ = 9.39 ppm；故推斷訊號在δ = 9.34 ppm的結構為Z型。
Bppb-Re-Ph之U型結構出現1MLCTRe→Bppb的吸收峰 (~360 nm)，放光位置則是在500 nm (在CH2Cl2下量子產率為0.297，放光生命週期為2.34 µs)。
1H NMR圖譜顯示來自BppEb吡啶的碳上氫訊號只有一組，BppEb-Re-Ph的δ = 9.36 ppm，BppEb-Re-L1的δ = 9.40 ppm，參考Bppb系列的1H NMR位置，推論BppEb-Re-Ph的結構為Z型，BppEb-Re-L1的結構為U型。
;A series of dinuclear rhenium(I) tricarbonyl complexes [Bppb-Re-R] and [BppEb-Re-R] (R = Br, Ph (4-phenylpyridine), L1 (2-hexyl-7-pyridin-4-yl-benzo[lmn][3,8]phenanthroline-1,3,6,8-tetraone) containing bidentate 1,3-bis((3-(pyridine-2-yl)-1H-pyrazol-1-yl)methyl)benzene (Bppb) or 1,2-bis(2-(3- (pyridine-2-yl)-1H-pyrazol-1-yl)ethyl)benzene (BppEb) ligand has been designed and synthesized.
The 1H NMR spectra of Bppb-Re-Ph and Bppb-Re-L1 showed distinct signals, indicative of both Bppb-Re-Ph and Bppb-Re-L1 possessing two conformations. The single crystal of Bppb-Re-Ph for X-ray diffraction with U-shaped conformation was grown by diffusing diethyl ether into an acetone solution. The 1H NMR spectrum of the U-shaped isomer showed the signal at δ = 9.39 ppm. Thus, the signal located at δ = 9.34 ppm may be attributed to the conformation isomer of Z form.
The absorption spectrum of Bppb-Re-Ph with U-shaped conformation exhibited broad absorption between 330 and 390 nm with a predominant character of 1MLCTRe→Bppb transition and the emission spectrum displayed at 500 nm. (quantum yield 0.279, lifetime 2.34 µs in CH2Cl2)
Comparing to those of Bppb series, the 1H NMR spectra show that both BppEb-Re-Ph and BppEb-Re-L1 may have only one conformation. |
