Design and synthesis of bipyridine platinum(II) bisalkynyl fullerene donor-chromophore-acceptor triads with ultrafast charge separation

Sai Ho Lee, Chris Tsz Leung Chan, Keith Man Chung Wong, Wai Han Lam, Wai Ming Kwok, Vivian Wing Wah Yam

Research output: Journal article publicationJournal articleAcademic researchpeer-review

57 Citations (Scopus)

Abstract

Donor-chromophore-acceptor 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)-C 60 shows ultrafast triplet-triplet energy transfer from the 3MLCT/LLCT excited state within 4 ps to give the 3C 60* 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.
Original languageEnglish
Pages (from-to)10041-10052
Number of pages12
JournalJournal of the American Chemical Society
Volume136
Issue number28
DOIs
Publication statusPublished - 16 Jul 2014

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

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