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Self-Assembly Solid-State Enhanced Red Emission of Quinolinemalononitrile: Optical Waveguides and Stimuli Response
journal contribution
posted on 2013-01-09, 00:00 authored by Chuanxing Shi, Zhiqian Guo, Yongli Yan, Shiqin Zhu, Yongshu Xie, Yong Sheng Zhao, Weihong Zhu, He TianThe fluorescence of luminescent emitters is often quenched
in the solid state, because of the typical aggregation-caused quenching
(ACQ) effect, which is a thorny obstacle to high-performance organic
optoelectronic materials. The exploration of solid-state enhanced
long wavelength, red-emitting chromophores, especially possessing
one-dimensional (1D) assembly features, is of great importance. Interestingly,
an excellent solid-state enhanced red emission system (denoted as
ED) based on quinolinemalononitrile has been developed via the delicate
modification of the conventional ACQ dicyanomethylene-4H-pyran (DCM) derivative (denoted as BD) through crystal engineering.
ED exhibits extraordinary self-assembly property in a variety of solvents,
even realizing the “waving ribbons” with a length of
6 mm and a diameter of 10 μm. Crystal analysis shows that the
CH···π and CH···N supramolecular
interactions of ED contribute to the twisted self-assembly solid-state
enhanced emission phenomenon. However, for BD, strong face-to-face
stacking leads to fluorescence quenching in the solid state. Because
of such easy assembly and strong solid-state emission properties,
application for optical waveguides of ED is realized with a low optical
loss. Stimuli-responsive behavior is also elaborated with color change
between orange and red by grinding/fuming or pressing/heating.