(1) 錸聯比啶三羥基咪錯合物的光物理研究 (2) 光引發的氧原子轉移反應的研究

(1) Photophysical Properties of Re(diimine)(CO)3Im (2) Photoinduced Oxygen Atom Transfter

林人傑(Lin Jen-Chieh)

指導教授 ： 張一知

國立臺灣師範大學/理學院/化學系/博士(2001年)

摘要

錸聯比啶三羥基咪坐錯合物，如Re(LL)(CO)3(Im)+ (LL = 2,2’- bipyridine (bpy)，1,10-phenanthroline (phen)，4,4’-dicarboxyl- 2,2’-bipyridine (bpy(COOH)2)，4’-methyl-2,2’-bipyridine-4-carboxylic acid (mbpy(COOH) 及bathophenanthroline disulfonic acid (phen(phSO3H)2)) 五種錯合物已被合成，此類錯合物的紫外可見光譜在350 - 380 nm 有金屬到配位基 (MLCT) 的躍遷吸收，其冷光光譜最大值約在580 - 625 nm。錸聯比啶三羥基咪坐錯合物在有機溶劑中明顯有較強的磷光及較長冷光生命期，但是在水溶液的磷光與其生命期短很多。
乙醯化微過氧化酵素 (acetyl microperoxidase-8, AcMP8) 於氰甲烷與pH = 8緩衝溶液的混合溶劑中，在強氧化劑存在下，可被氧化成FeIV=O或FeIII-porphyrin+•，再進行氧原子轉移反應，接受氧原子的有機受質為反式-二苯乙烯，產物為苯甲醛。強氧化劑的生成是利用光激發光敏劑 (如Ru(bpy)3Cl2)，藉由電子接受者 (如quinone，methyl viologen，FAD) 的存在的情況下，而產生的Ru(bpy)33+。
碳60由光激發後，會先產生單重態的碳60，在經過分子內的轉換而得到三重態的碳60。三重態碳60很容易與氧氣反應，得到反應性很好單重態的氧分子。此單重態氧分子可以氧化硫醚生成硫氧化物。反應的產率及催化劑碳60的光穩定性與溶劑有非常大的關係，當使用甲苯與甲醇以低於3:1的比例混合時，碳60在照光後不會被分解。溶液中若含質子性溶劑，如甲醇或水，則會加快氧化反應且產率較高。

關鍵字

錸錯合物 ； 微過氧化酵素 ； 光引發反應 ； 碳六十

並列摘要

Abstract
Five Re(LL)(CO)3(Im)+ complexes have been prepared, where LL are 2,2’-bipyridine (bpy), 1,10-phenanthroline (phen), 4,4’-dicarboxyl- 2,2’-bipyridine (bpy(COOH)2), 4’-methyl-2,2’-bipyridine-4-carboxylic acid (mbpy(COOH) and bathophenanthroline disulfonic acid (phen(phSO3H)2). All complexes exhibit metal-to-ligand charge-transfer (MLCT) absorption in the 350 - 380 nm range. Exciting the MLCT transition results in orange luminescence. The 3MLCT emission maxima for these complex range from 580 - 625 nm in aqueous solution. These complexes have higher emission quantum yield and longer lifetime in organic solvent than in aqueous solution.
Acetyl microperoxidase-8 (AcMP8, hydrolysis product of cytochrome c) resembles the heme environment of peroxidase on both structure and activities. Photoinduced oxidation of the FeIII to ferryl (FeIV=O) has been observed for AcMP8 in pH=8 buffer solution. In organic-aqueous mixed solvent system, catalytic oxygenation of stilbene by AcMP8 is observed. The system involves a sensitizer (i.e. Ru(bpy)32+), an electron acceptor (e.g. benzoquinone), a catalyst (i.e. AcMP8), and stilbene. Benzaldehyde is the major product.
Singlet C60 is generated from photoexcitation and decays to triplet C60 via intersystem crossing. Triplet C60 readily transfers its energy to molecule oxygen and produces singlet oxygen. Singlet oxygen is a powerful oxygen donor, and therefore, reacts with dimethyl sulfide to give dimethyl sulfoxide. Yield of photoproduct and sensitizer stability are highly dependent on the solvent composition. C60 is most stable in a solution of 3 to 1 toluene/methanol mixture. With the presence of a protic solvent (e.g. methanol, water), the oxygenated reaction rate of dimethyl sulfide is faster.

並列關鍵字

Re complex ； microperoxidase ； photoinduced reaction ； C60