Department of Chemistry, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599, United States.
School of Chemistry and Biochemistry, School of Materials Science and Engineering, Center for Organic Photonics and Electronics, Georgia Tech Polymer Network, Georgia Institute of Technology , Atlanta, Georgia 30332, United States.
ACS Appl Mater Interfaces. 2017 May 17;9(19):16651-16659. doi: 10.1021/acsami.7b02713. Epub 2017 May 4.
Photoinduced electron injection, intra-assembly electron transfer, and back-electron transfer are investigated in a single-site molecular assembly formed by covalently linking a phosphonated terthiophene (T) chromophore to a Ru(terpyridine)(bipyridine)(L) (L = MeCN or HO) water oxidation catalyst adsorbed onto a mesoporous metal-oxide (MO) film. Density functional theory calculations of the T-trpy-Ru-L assembly indicate that the molecular components are strongly coupled with enhanced low-energy absorptions owing to the presence of an intraligand charge transfer (ILCT) transition between the T and trpy moieties. Ultrafast spectroscopy of the MO//T-trpy-Ru-L assemblies reveals that excitation of the surface-bound T chromophore results in ps-ns electron injection into the metal-oxide conduction band. Electron injection is followed by rapid (<35 ps) intra-assembly electron transfer from the Ru catalyst to regenerate the T chromophore with subsequent back-electron transfer on the microsecond time scale.
在通过将膦酸化的三联噻吩 (T) 发色团共价连接到吸附在介孔金属氧化物 (MO) 薄膜上的 Ru(三联吡啶)(联吡啶)(L) (L = MeCN 或 HO) 水氧化催化剂上形成的单分子组装体中，研究了光致电子注入、组装内电子转移和反向电子转移。T-trpy-Ru-L 组装体的密度泛函理论计算表明，由于 T 和 trpy 部分之间存在配体内电荷转移 (ILCT) 跃迁，分子组件强烈耦合，具有增强的低能量吸收。MO//T-trpy-Ru-L 组装体的超快光谱表明，表面结合的 T 发色团的激发导致 ps-ns 电子注入到金属氧化物导带中。电子注入后，从 Ru 催化剂快速(<35 ps)进行组装内电子转移，从 Ru 催化剂再生 T 发色团，随后在微秒时间尺度上进行反向电子转移。
