화학공학소재연구정보센터
Industrial & Engineering Chemistry Research, Vol.55, No.6, 1801-1807, 2016
Synthesis and Characterization of Novel 1,4-Bis(carbazolyl)benzene Derivatives with Blue-Violet Two-Photon-Excited Fluorescence
Novel fluorescent two-photon absorption molecules containing bis(carbazolyl)benzene as the central unit and phenylethynyl moieties as peripheral groups (Cz-Ps) are synthesized and characterized. In these molecules, two carbazolyl moieties are linked with benzene at the 9-position and synthesized by a concise process involving nucleophilic substitution between the cyclopentadienyliron complexes of dichloroarenes and phenylethynyl carbazole, followed by photolysis. The optimal structures of Cz-Ps reveal that two carbazolyl rings linked by a benzene ring are not planar. This feature prevents the electron conjugation of the molecule from extending throughout the whole molecule and allows Cz-Ps to realize blue-violet emissions and high fluorescence quantum yield. With increasing number of conjugated phenylacetylene structures in Cz-Ps, the maximal absorption and emission peaks were red-shifted. The quadrupolar compound DMoCz-P shows strong one-photon and two photon activities. The resulting molecules are also thermally stable with high glass transition temperatures due to the rigid bicarbazole central unit. This work has demonstrated that using bis(carbazolyl)benzene as central building block could enhance two-photon absorption (TPA) performance and also provides a possible general synthetic strategy for a series of bis(carbazolyl)benzene derivatives, which would advance the understanding of the rational design of new organic optical materials.