Design and Synthesis of Bipyridine Platinum(II) Bisalkynyl Fullerene Donor鈥揅hromophore鈥揂cceptor Triads with Ultrafast Charge Separation
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- 作者：Sai-Ho Lee ; Chris Tsz-Leung Chan ; Keith Man-Chung Wong ; Wai Han Lam ; Wai-Ming Kwok ; Vivian Wing-Wah Yam
- 刊名：Journal of the American Chemical Society
- 出版年：2014
- 出版时间：July 16, 2014
- 年：2014
- 卷：136
- 期：28
- 页码：10041-10052
- 全文大小：658K
- ISSN：1520-5126
文摘
Donor鈥揷hromophore鈥揳cceptor triads, (PTZ)2-Pt(bpy)-C60 and (tBuPTZ)2-Pt(bpy)-C60, along with their model compound, (Ph)2-Pt(bpy)-C60, have been synthesized and characterized; their photophysical and electrochemical properties have been studied, and the origin of the absorption and emission properties has been supported by computational studies. The photoinduced electron transfer reactions have been investigated using the femtosecond and nanosecond transient absorption spectroscopy. In dichloromethane, (Ph)2-Pt(bpy)-C60 shows ultrafast triplet鈥搕riplet energy transfer from the 3MLCT/LLCT excited state within 4 ps to give the 3C60* state, while in (PTZ)2-Pt(bpy)-C60 and (tBuPTZ)2-Pt(bpy)-C60, charge-separated state forms within 400 fs from the 3MLCT/LLCT excited state with efficiency of over 0.90, and the total efficiency with the contribution of 3C60* is estimated to be 0.99. Although the forward electron transfer reactions are very rapid, the charge-separated state recombines to the singlet ground state at a time of hundreds of nanoseconds because of the difference in spin multiplicity between the charge-separated state and the ground state.