标题：Novel planar and star-shaped molecules: Synthesis, electrochemical and photophysical properties
作者：Niu, Qingfen; Lu, Yunqiang; Sun, Hongjian; Li, Xiaoyan
作者机构：[Niu, Qingfen; Lu, Yunqiang; Sun, Hongjian; Li, Xiaoyan] Shandong Univ, Sch Chem & Chem Engn, Jinan 250100, Peoples R China.
通讯作者地址：[Li, XY]Shandong Univ, Sch Chem & Chem Engn, Shanda Nanlu 27, Jinan 250100, Peoples R China.
来源：SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
关键词：Planar molecule; Star-shaped molecule; Acetylenic spacer;; Aggregate-enhanced emission effect; Aggregation-caused quenching effect;; Photovoltaic material
摘要：Three novel planar and star-shaped molecules containing thiophene-functionalized group and acetylenic spacers, 4((5 ''-iodo-[2,2':5',2 ''-terthiophen]-5-yl)ethynyl)aniline (I3TEA), 4,4'-([2,2':5',2 ''-terthiophene]-5,5 ''-diylbis(ethyne-2,1-diyl))dianiline (3TDDA), 1,3,5-tris((5-((trimethylsilyl)ethynyl)thiophen-2-yl)-ethynyl)benzene (TETEB) were synthesized through Sonogashira coupling reaction. Their photophysical and electrochemical properties were explored by UV-vis, photoluminescence (PL) emission and DFT calculation. Three compounds possess unusual phenomena of PL, with the concentration of gradually decreased, the intensity of PL firstly increased and then decreased, this may be due to the aggregate-enhanced emission (AEE) effect and aggregation-caused quenching (ACQ) effect. Their spectroscopic data demonstrate that D-pi-A-pi-D structured organic dye 3TDDA based on NH2 as donor units and 3T as acceptor units with acetylenic spacers it-conjugated chain between them exhibits good luminescent properties. Dye I3TEA with donor(D) acceptor(A) structure shows good charge transfer because of amino functional group and iodine atom. Octupolar organic pi-conjugated star-shaped molecule TETEB possesses excellent luminescent properties because of its unique structure applied in the optoelectronic field. The redox curves and results of DFT calculations suggest that three compounds have low ionization potential and low E-oxd. All the good properties demonstrate three compounds could be promising candidates for photovoltaic materials. (c) 2013 Elsevier B.V. All rights reserved.