Synthesis and Photoinduced Intramolecular Processes of Light-Harvesting Silicon Phthalocyanine–Naphthalenediimide–Fullerene Connected Systems
✍ Scribed by Mohamed E. El-Khouly; Jung Hoon Kim; Kwang-Yol Kay; Chan Soo Choi; Osamu Ito; Shunichi Fukuzumi
- Book ID
- 101837799
- Publisher
- John Wiley and Sons
- Year
- 2009
- Tongue
- English
- Weight
- 489 KB
- Volume
- 15
- Category
- Article
- ISSN
- 0947-6539
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Fast moving: A new pentad (see figure) composed of silicon phthalocyanine (SiPc), as electron donor, that is connected with two units of naphthalenediimide (NDI) and fullerene C~60~, as electron acceptors, undergoes fast and efficient charge‐separation processes via the NDI and SiPc singlet excited states.magnified image
Photoinduced intramolecular processes of a newly synthesized pentad composed of silicon phthalocyanine (SiPc) that is connected with two units of naphthalenediimide (NDI) and fullerene C~60~ to form SiPc‐(NDI)~2~‐(C~60~)~2~ have been studied and the results are compared with the reference compounds, namely, the SiPc‐(NDI)~2~ triad and NDI‐C~60~ dyad. Upon photoexcitation, the main quenching pathway in polar solvents involved electron transfer via the singlet excited states of SiPc‐(NDI)~2~‐(C~60~)~2~ and SiPc‐(NDI)~2~, but not NDI‐C~60~ for which the energy transfer is dominant. The occurrence of electron‐transfer processes of SiPc‐(NDI)~2~‐(C~60~)~2~ and SiPc‐(NDI)~2~ were studied by time‐resolved emission and transient absorption techniques and confirmed by redox measurements and molecular orbital calculations with ab initio B3 LYP/3–21G(*) methods. Fast and efficient charge‐separation processes via the singlet excited states of NDI and SiPc were monitored, followed by charge recombination to populate the C~60~ and SiPc triplet states. The lifetimes of charge‐separated states were estimated as 1000 and 250 ps for SiPc‐(NDI)~2~‐(C~60~)~2~ and SiPc‐(NDI)~2~, respectively.