Elucidation of photo excited state of Ru complex by time-resolved XAFS

利用时间分辨X射线吸收精细结构（XAFS）研究了[RuII（bpy）3]2+三重态金属-配体电荷转移（3 MLCT）态的瞬态结构变化.以前对3 MLCT态的研究主要是使用光学光谱方法进行的，很难用原子分辨率估计分子结构。XAFS通过扩展X射线吸收精细结构（EXAFS）揭示了吸收原子与配位原子之间的原子距离。XAFS还通过X射线近边结构（XANES）给出了吸收原子的价态。结果显示了瞬态电子态和局域结构的详细信息，这是难以跟踪的常规光谱。

Time-resolved X-ray absorption fine structure (XAFS) was conducted to investigate transient structure change in the triplet metal-to-ligand charge transfer (3MLCT) state of [RuII(bpy)3]2+. Previous studies of the 3MLCT state have mainly been performed using optical spectroscopic methods, from which it is difficult to estimate the molecular structure with atomic resolution. XAFS reveals the atomic distance between the absorbing atom and coordinated atoms via extended X-ray absorption fine structure (EXAFS). XAFS gives also the valence of absorbing atom by X-ray near edge structure (XANES). The results show the detailed information about the transient electronic state and local structure that is difficult to track by conventional spectroscopy.