TY - JOUR
T1 - Real-time observation of intersystem crossing induced by charge recombination during bimolecular electron transfer reactions
AU - Alsam, Amani A.
AU - Aly, Shawkat Mohammede
AU - Parida, Manas R.
AU - Alarousu, Erkki
AU - Cao, Zhen
AU - Cavallo, Luigi
AU - Mohammed, Omar F.
N1 - KAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This work was supported by King Abdullah University of Science and Technology (KAUST). This work is also supported by Saudi Arabia Basic Industries Corporation (SABIC) grant RGC/3/2470-01.
PY - 2016/9/21
Y1 - 2016/9/21
N2 - Real-time probing of intersystem crossing (ISC) and triplet-state formation after photoinduced electron transfer (ET) is a particularly challenging task that can be achieved by time-resolved spectroscopy with broadband capability. Here, we examine the mechanism of charge separation (CS), charge recombination (CR) and ISC of bimolecular photoinduced electron transfer (PET) between poly[(9,9-di(3,3′-N,N’-trimethyl-ammonium) propyl fluorenyl-2,7-diyl)-alt-co-(9,9-dioctyl-fluorenyl-2,7-diyl)] diiodide salt (PFN) and dicyanobenzene (DCB) using time-resolved spectroscopy. PET from PFN to DCB is confirmed by monitoring the transient absorption (TA) and infrared spectroscopic signatures for the radical ion pair (DCB─•-PFN+•). In addition, our time-resolved results clearly demonstrate that CS takes place within picoseconds followed by CR within nanoseconds. The ns-TA data exhibit the clear spectroscopic signature of PFN triplet-triplet absorption, induced by the CR of the radical ion pairs (DCB─•-PFN+•). As a result, the triplet state of PFN (3PFN*) forms and subsequently, the ground singlet state is replenished within microseconds. © 2016
AB - Real-time probing of intersystem crossing (ISC) and triplet-state formation after photoinduced electron transfer (ET) is a particularly challenging task that can be achieved by time-resolved spectroscopy with broadband capability. Here, we examine the mechanism of charge separation (CS), charge recombination (CR) and ISC of bimolecular photoinduced electron transfer (PET) between poly[(9,9-di(3,3′-N,N’-trimethyl-ammonium) propyl fluorenyl-2,7-diyl)-alt-co-(9,9-dioctyl-fluorenyl-2,7-diyl)] diiodide salt (PFN) and dicyanobenzene (DCB) using time-resolved spectroscopy. PET from PFN to DCB is confirmed by monitoring the transient absorption (TA) and infrared spectroscopic signatures for the radical ion pair (DCB─•-PFN+•). In addition, our time-resolved results clearly demonstrate that CS takes place within picoseconds followed by CR within nanoseconds. The ns-TA data exhibit the clear spectroscopic signature of PFN triplet-triplet absorption, induced by the CR of the radical ion pairs (DCB─•-PFN+•). As a result, the triplet state of PFN (3PFN*) forms and subsequently, the ground singlet state is replenished within microseconds. © 2016
UR - http://hdl.handle.net/10754/622240
UR - http://www.sciencedirect.com/science/article/pii/S0143720816307768
UR - http://www.scopus.com/inward/record.url?scp=84989206836&partnerID=8YFLogxK
U2 - 10.1016/j.dyepig.2016.09.049
DO - 10.1016/j.dyepig.2016.09.049
M3 - Article
SN - 0143-7208
VL - 136
SP - 881
EP - 886
JO - Dyes and Pigments
JF - Dyes and Pigments
ER -