聯吡啶釕錯合物在陰離子感測器與光催化溴離子氧化之應用

The Applications of Ruthenium Polypyridyl Complexes to Anion Sensor and Photocatalytic Oxidation of Bromide

蔡昀達(Tsai Yun-Da)

指導教授 ： 張一知

國立臺灣師範大學/理學院/化學系/博士(2017年)

https://doi.org/10.6345/NTNU202202224

摘要

本論文研究聯吡啶釕金屬錯合物的光物理性質及其應用，應用之一為氟離子感測器，另一則是利用 flash-quench technique 來了解三價釕金屬錯合物與溴離子及碘離子之間的電子傳遞速率，以便更進一步探討光敏性染料太陽能電池的反應機制。
氟離子感測器實驗所選擇之錯合物是含有羥基的 [Ru(bpy)2((OH)2bpy)](PF6)2，其電子吸收光譜、冷光光譜、生命期、量子產率以及電化學氧化還原性質均已被測量，且發現錯合物對於氟離子具有獨特之選擇性。利用 Job's plot 及滴定實驗可以得知錯合物與氟離子之間的反應比例，在相同濃度 (10-4 M) 但使用不同溶劑的條件下，Ru:F ─ 之比例為 1:3 (乙腈) 及 1:2 (DMSO)，顯示溶劑效應對於此偵測反應有相當之影響性。而在相同溶劑 (乙腈) 但不同濃度的條件下，Ru:F ─ 之比例為 1:3 (10-4 M) 及 1:4 (10-3 M)，同樣的現象在 DMSO 作為溶劑的情況下也有被觀察到，Ru:F ─ 之比例為 1:2 (10-4 M) 及 1:4 (10-2 M)，也證實了濃度效應在此反應中深具影響力。利用冷光光譜的偵測，可使錯合物對於氟離子之偵測極限提升至 10-6 M。
錯合物 [Ru(bpy)3](PF6)2 (1)、[Ru(bpy)2(deeb)](PF6)2 (2)、[Ru(deeb)2(dmbpy)](PF6)2 (3)、[Ru(deeb)2(bpy)](PF6)2 (4)、[Ru(deeb)3](PF6)2 (5) 及 [Ru(deeb)2(bpz)](PF6)2 (6) 則是利用於研究電子傳遞實驗，所有錯合物的光物理及氧化還原性質均已測量。錯合物 1-6 照光激發後與氧化淬熄劑 (ArN2+ 或 MV2+) 先進行雙分子淬熄反應，所得到之淬熄速率常數 kq 介於 1.02 x 107 及 1.13 x 109 M-1 s-1之間，相對應其淬熄反應之驅動力介於 0.26 到 0.76 eV 間是相當符合 driving force dependence，另外所測得 sphere-of-action 之有效半徑分別為 3.2 (ArN2+) 以及 2.0 nm (MV2+) 也與驅動力有正相關性。而淬熄後得到的三價釕金屬錯合物再與溴離子或碘離子進行電子傳遞之反應，與溴離子反應之電子傳遞速率常數 kBr 依序由 1.17 x 108 M-1 s-1 (0.43 eV) 增加至 1.11 x 1010 M-1 s-1 (0.73 eV)，也是符合 driving force dependence，但三價釕金屬錯合與碘離子反應之電子傳遞速率常數 kI 卻差異不大，約介於 1.1-3.0 x 1010 M-1 s-1 之間。

關鍵字

陰離子感測器 ； 溴離子氧化 ； 光催化 ； 釕金屬錯合物

並列摘要

We have studied the photophysical properties and applications of ruthenium(II) trisbipyridyl complexes. The first part is about fluoride sensor. The other one we want to investigate the electron transfer rate constants of ruthenium(III) with bromide and iodide utilize the flash-quench technique for the mechanism of DSSC.
The complex with hydroxyl groups, [Ru(bpy)2((OH)2bpy)](PF6)2, is employed for fluoride sensor. Photophysical properties are carried out and indicating that this complex is unique to fluoride ion. Job's plot and titration experiments shows the ratios of Ru:F ─ are 1:3 in MeCN and 1:2 in DMSO while the concentrations are about 10-4 M. It suggests solvent effect in this reaction. In different concentration, the ratios of Ru:F ─ are 1:3 (10-4 M) and 1:4 (10-3 M) in MeCN. The same phenomenon is observed in DMSO, the ratios of Ru:F ─ are 1:2 (10-4 M) and 1:4 (10-2 M). The concentration effect is also present here. The detection limit is about 10-6 M to fluoride ion.
Six ruthenium complexes, [Ru(bpy)3](PF6)2 (1), [Ru(bpy)2(deeb)](PF6)2 (2), [Ru(deeb)2(dmbpy)](PF6)2 (3), [Ru(deeb)2(bpy)](PF6)2 (4), [Ru(deeb)3](PF6)2 (5) and [Ru(deeb)2(bpz)](PF6)2 (6) have been employed to investigate the electron transfer. The oxidation potential for complexes 1-6 are 1.26, 1.36, 1.42, 1.46, 1.56 and 1.66 V vs SCE, respectively. Bimolecular quenching rate constants (kq) of complex 1-6 by quenchers, ArN2+ and MV2+, are between 1.02 x 107 and 1.13 x 109 M-1 s-1. The radii of sphere-of-action are 3.2 (ArN2+) and 2.0 nm (MV2+). Electron transfer rate constants (kBr) of ruthenium(III) with bromide are from 1.17 x 108 M-1 s-1(0.43 eV) to 1.11 x 1010 M-1 s-1(0.73 eV). The results are dependent on driving force. Electron transfer rate constants (kI) of ruthenium(III) with iodide are about 1.1-3.0 x 1010 M-1 s-1. The similar rate constants are because of diffusion limit in MeCN.

並列關鍵字

anion sensor ； oxidation of bromide ； photocatalysis ； ruthenium complexes

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