Absorption spectra related to heterogeneous electron transfer reactions: the perylene TiO2 system.
Absorption spectra related to heterogeneous electron transfer reactions: the perylene TiO2 system.
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DOI：
10.1021/jp0500539
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发表时间：
2005-04
期刊：
影响因子：
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通讯作者：
Luxia Wang;R. Ernstorfer;F. Willig;V. May
中科院分区：
文献类型：
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作者：
Luxia Wang;R. Ernstorfer;F. Willig;V. May
从理论上和实验上研究了染料-半导体体系（苝- TiO2）的线性吸收光谱。该体系表现出超快的光致非均相电子转移（HET）。通过应用吸光度的时间相关公式，对测量数据进行了理论分析。各自的电子-振动波包传播充分解释了TiO2与导带连续体的电子耦合，并基于单反应坐标模型（对应于量子能量为1370 cm（-1）的苝平面内C-C拉伸振动）。通过插入不同的桥锚基团，导致HET的电子耦合是不同的。染料在溶剂中的吸光度和由于与传导带连续体的耦合而导致的振动过程的线展宽趋势在所有被研究的桥锚基团类型中都得到了再现。从显示谱线加宽的吸光度计算中推导出的热交换率与瞬态吸收光谱的定性趋势一致。
Linear absorption spectra of dye-semiconductor systems (perylene attached to nanostructured TiO2) are studied theoretically and experimentally. The systems show ultrafast photoinduced heterogeneous electron transfer (HET). By applying a time-dependent formulation of the absorbance, the theoretical analysis of the measured data is carried out. The respective electron-vibrational wave packet propagation fully accounts for the electronic coupling to the conduction band continuum of TiO2 and is based on a single-reaction-coordinate model (corresponding to a perylene in-plane C-C stretching vibration with a quantum energy of 1370 cm(-1)). By the insertion of different bridge-anchor groups, the electronic coupling responsible for HET is varied. The dye absorbance in a solvent and the trends in the line broadening of the vibrational progression due to the coupling to the conduction band continuum are reproduced for all investigated types of bridge-anchor groups. HET rates deduced from the calculations on the absorbance displaying line broadenings follow the qualitative trend obtained from transient absorption spectra.