Synthesis and photoinduced intramolecular processes of light-harvesting silicon phthalocyanine-naphthalenediimide-fullerene connected systems.
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.
Department of Material and Life Science, Graduate School of Engineering, Osaka University, SORST, Japan Science and Technology Agency (JST), Suita, Osaka 565-0871, Japan.
Mohamed E
ME
El-Khouly
Jung Hoon
JH
Kim
Kwang-Yol
KY
Kay
Chan Soo
CS
Choi
Osamu
O
Ito
Shunichi
S
Fukuzumi
D004735:Energy Transfer; D037741:Fullerenes; D007094:Imides / Q000737:chemistry*; D007211:Indoles / Q000737:chemistry*; D007700:Kinetics; D008956:Models, Chemical; D008958:Models, Molecular; D015394:Molecular Structure; D009281:Naphthalenes / Q000737:chemistry*; D017646:Organosilicon Compounds / Q000737:chemistry*; D010777:Photochemistry; D013056:Spectrophotometry, Ultraviolet
D037741:Fullerenes; D007094:Imides; D007211:Indoles; D009281:Naphthalenes; D017646:Organosilicon Compounds; C082854:silicon phthalocyanine; C542131:naphthalenediimide