Photoinduced Intramolecular Tryptophan Oxidation and Excited-State Behavior of [Re(L-AA)(CO)<sub>3</sub>(α-diimine)]<sup>+</sup>(L = Pyridine or Imidazole, AA = Tryptophan, Tyrosine, Phenylalanine)
作者:Ana María Blanco-Rodríguez、Mike Towrie、J. Sýkora、Stanislav Záliš、Antonín Vlček
DOI:10.1021/ic200252z
日期:2011.7.4
complexes [Re(L-AA)(CO)3(N,N)]+ (N,N = bpy, phen) containing an aromatic amino acid (AA), phenylalanine (Phe), tyrosine (Tyr), or tryptophan (Trp), linked to Re by a pyridine-amido or imidazole-amido ligand L have been synthesized and their excited-state properties investigated by nanosecond time-resolved IR (TRIR) and emission spectroscopy. Near-UV optical excitation populates a ReI(CO)3→N,N 3MLCT excited
Re I羰基-二亚胺络合物[Re(L-AA)(CO)3(N,N)] +(N,N = bpy,phen)包含芳香族氨基酸(AA),苯丙氨酸(Phe),酪氨酸(Tyr合成了通过吡啶-酰胺基或咪唑-酰胺基配体L与Re连接的色氨酸(Trp)或色氨酸(Trp),并通过纳秒时间分辨IR(TRIR)和发射光谱研究了它们的激发态性质。近紫外光激发形成Re I(CO)3 →N,N 3 MLCT激发态* [Re II(L-AA)(CO)3(N,N •–)] +。在Phe和Tyr配合物的情况下,观察到衰变到基态(寿命为50-300 ns)是唯一的激发态失活过程,而含Trp的物质经历Trp(吲哚)→* Re II电子转移(ET )产生电荷分离(CS)状态[Re I(L-Trp •+)(CO)3(N,N •–)] +。取决于L,N,N和溶剂,ET的寿命为8–40 ns。CS状态的特征是ν(CO)IR波段从其各自的基