121st General Meeting of the KCS

Type Poster Presentation
Area Physical Chemistry
Room No. Event Hall
Time 4월 20일 (금요일) 11:00~12:30
Code PHYS.P-182
Subject Charge Transfer-Induced Torsional Dynamics in the Excited State of 2,6-Bis(diphenylamino)anthraquinone
Authors Jungkweon Choi*, Doo-Sik Ahn1, DAE WON CHO2, Hyotcherl Ihee3,*
Center for Nanomaterials and Chemical Reactions, Institute for Basic Science, Korea
1Center for Nanomaterials and Chemical reactions, Institute for Basic Science, Korea
2Department of Advanced Materials Chemistry, Korea University, Korea
3Department of Chemistry, Korea Advanced Institute of Science and Technology, Korea
Abstract Intramolecular charge transfer (ICT) in a multibranched push−pull chromophore is a key photophysical process which is attracting attention due to its relevance to the development of highly efficient organic light-emitting diodes, but the excited-state dynamics of multibranched push−pull chromophores is still unclear. Here, we studied the excited state dynamics of 2,6-bis(diphenylamino)anthraquinone (DPA-AQ-DPA) using femtosecond transient absorption spectroscopy and singular value decomposition analysis. The emission of DPA-AQ-DPA exhibits large Stokes shifts with increasing solvent polarity, indicating that the emission can be attributed to an ICT process. The charge separated (CS) state formed by ICT undergoes torsional dynamics, involving twisting between D and A, resulting in the formation of a twisted charge separated state (CStwisting). This twisting reaction between D and A is accelerated in high-polarity solvents compared with that in low-polarity solvents. This result indicates that the energy levels of CS and CStwisting states can be adjusted by controlling aspects of the local environment, such as solvents, so that intersystem crossing can be either inhibited or promoted.
E-mail dsahn@ibs.re.kr