含胺取代之聯吡啶釕錯化合物之光物理性質研究

Abstract

本論文合成六種含有4,4’-dabpy與5,5’-dabpy兩種胺基取代的釕金屬錯合物。各為 [Ru(4,4’-dabpy)bpy2]2+、[Ru(4,4’-dabpy)2bpy]2+、[Ru(4,4’-dabpy)3]2+、[Ru(5,5’-dabpy)bpy2]2+、[Ru(5,5’-dabpy)2bpy]2+ 和 [Ru(5,5’-dabpy)3]2+。

實驗結果顯示，4,4’-dabpy為配位基時，會造成吸收光譜紅位移，隨著4,4’-dabpy配位的增加，MLCT band的吸收分別為471 nm、481 nm和502 nm。而5,5’-dabpy為配位基時，會造成吸收光譜藍位移，隨著5,5’-dabpy配位的增加，MLCT band的吸收分別為452 nm、450 nm、420 nm。

當胺取代配位基增多時，釕金屬錯化合物在鹼中的量子產率較在酸中大。當胺取代配位基減少時，釕金屬錯化合物在鹼中的量子產率較在酸中小。

釕金屬錯化合物的吸收光譜與冷光光譜對酸鹼沒有明顯的變化。從酸到鹼中，只有 [Ru(5,5’-dabpy)3]2+ 的最大吸收波長會從631 nm shift 到572 nm。

4,4’-dabpy為配位基時，低溫冷光光譜在酸和鹼中差別較大。 隨著4,4’-dabpy 配位的增加，低溫冷光光譜最大吸收波長在酸中分別為625、628、668 nm，在鹼中分別為656、705、676 nm。5,5’-dabpy為配位基時，隨著5,5’-dabpy配位的增加，max 在酸中分別為606、586、567 nm，在鹼中分別為590、600、554 nm。

Ruthenium(II) polypyridyl complexes with amino substituted bipyridine ligands have been synthesized. Two ligands: 4,4’-diamino-2,2’-bipyridine (4,4’-dabpy) and 5,5’-diamino-2,2’-bipyridine (5,5’-dabpy) and six complexes: Ru(4,4’-dabpy)3, Ru(4,4’-dabpy)2bpy, Ru(4,4’-dabpy)bpy2, Ru(5,5’-dabpy)3, Ru(5,5’-dabpy)2bpy, and Ru(5,5’-dabpy)bpy2 were prepared.

The MLCT band of the complexes shifts to the red with increasing number of 4,4’-dabpy ligands. The absorption maxima are 471, 481 and 502 nm for Ru(4,4’-dabpy)bpy2, Ru(4,4’-dabpy)2bpy, and Ru(4,4’-dabpy)3, respectively. The MLCT band of the complexes with 5,5’-dabpy ligands shifts to the blue. The absorption maxima are 452, 450 and 420 nm for Ru(5,5’-dabpy)bpy2, Ru(5,5’-dabpy)2bpy, and Ru(5,5’-dabpy)3, respectively.

The emission quantum yield changes at various pH at room temperature. Generally, complexes with more amino bipyridine ligands have higher quantum yield in basic solution. Complexes with less amino bipyridine ligands have higher quantum yield in acidic solution.

The UV-Vis absorption and emission spectra of these complexes do not change from acidic to basic conditions at room temperature. Only the emission of Ru(5,5’-dabpy)3 shifts from 631 nm to 572 nm.

The emission maximum at 77 K shifts to higher energy at pH 2. The complexes with 5,5’-dabpy ligands are less sensitive to the pH than the complexes with 4,4’-dabpy lignds.