title: Uncovering the Intramolecular Emission and Tuning the Nonlinear Optical Properties of Organic Materials by Cocrystallization.
abstract: The spectroscopic and photophysical properties of organic materials in the solid-state are widely accepted as a result of their molecular packing structure and intermolecular interactions, such as J- and H-aggregation, charge-transfer (CT), excimer and exciplex. However, in this work, we show that Spe-F4DIB cocrystals (SFCs) surprisingly retain the energy levels of photoluminescence (PL) states of Spe crystals, despite a significantly altered molecular packing structure after cocrystallization. In comparison, Npe-F4DIB cocrystals (NFCs) with new spectroscopic states display different spectra and photophysical behaviors as compared with those of individual component crystals. These may be related to the molecular configuration in crystals, and we propose Spe as an "intramolecular emissive" material, thus providing a new viewpoint on light-emitting species of organic chromophores. Moreover, the nonlinear optical (NLO) properties of Npe and Spe are firstly demonstrated and modulated by cocrystallization. The established "molecule-packing-property" relationship helps to rationally control the optical properties of organic materials through cocrystallization.
authors.affiliation: Institute of Chemistry, Chinese Academy of Sciences (ICCAS), Beijing, 100190, China.|University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Weigang
authors.initials: W
authors.lastname: Zhu
authors.affiliation: National Center for Nanoscience and Technology, Beijing, 100190, China.
authors.forename: Lingyun
authors.initials: L
authors.lastname: Zhu
authors.affiliation: Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University & Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, China.
authors.forename: Lingjie
authors.initials: L
authors.lastname: Sun
authors.affiliation: Institute of Chemistry, Chinese Academy of Sciences (ICCAS), Beijing, 100190, China.
authors.forename: Yonggang
authors.initials: Y
authors.lastname: Zhen
authors.affiliation: Institute of Chemistry, Chinese Academy of Sciences (ICCAS), Beijing, 100190, China. dhl522@iccas.ac.cn.
authors.forename: Huanli
authors.initials: H
authors.lastname: Dong
authors.affiliation: National Center for Nanoscience and Technology, Beijing, 100190, China.
authors.forename: Zhixiang
authors.initials: Z
authors.lastname: Wei
authors.affiliation: Institute of Chemistry, Chinese Academy of Sciences (ICCAS), Beijing, 100190, China. huwp@iccas.ac.cn.|Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University & Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, China. huwp@iccas.ac.cn.
authors.forename: Wenping
authors.initials: W
authors.lastname: Hu
keywords: cocrystals; density functional theory; nonlinear optics; organic crystals; photophysics