Coordination and Electronic Structure of Ruthenium(II)-tris-2,2鈥?bipyridine in the Triplet Metal-to-Ligand Charge-Transfer Excited State Observed by Picosecond Time-Resolved Ru K-Edge XA

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• 作者：Tokushi Sato ; Shunsuke Nozawa ; Ayana Tomita ; Manabu Hoshino ; Shin-ya Koshihara ; Hiroshi Fujii ; Shin-ichi Adachi
• 刊名：The Journal of Physical Chemistry C
• 出版年：2012
• 出版时间：July 12, 2012
• 年：2012
• 卷：116
• 期：27
• 页码：14232-14236
• 全文大小：304K
• 年卷期：v.116,no.27(July 12, 2012)
• ISSN：1932-7455

文摘

Time-resolved X-ray absorption spectra of photoexcited ruthenium(II)-tris-2,2鈥?bipyridine ([Ru^II(bpy)₃]²⁺) in the triplet metal-to-ligand charge transfer (³MLCT) state are measured and analyzed to investigate transient structural changes directly related to the photophysical properties of the complex. The results from visible (400 nm) and UV (267 nm) excitation indicate that electrostatic interaction between the oxidized Ru atom and the reduced bipyridine ligand is the dominant factor affecting the Ru鈥揘 bond contraction. This thus leads to two groups of Ru ligand distances, one exhibiting the ground-state Ru鈥揘 distance and another yielding a slightly decreased Ru鈥揘 distance due to the localized MLCT excited state. The EXAFS analysis of the photoexcited complex was analyzed toward one single Ru鈥揘 distance, yielding a contraction of 0.04 (0.01) 脜 with an increased DW factor (corresponding to a 0.05 脜 mean increase).