Novel bifluorene based conjugated systems: synthesis and properties
- 作者：Roberto Grisorio ; Antonio Dell'Aquila ; Giuseppe Romanazzi ; Gian Paolo Suranna ; Piero Mastrorilli ; Pynalisa Cosma ; Domenico Acierno ; Eugenio Amendola ; Giuseppe Ciccarella and Cosimo Francesco Nobile
- 关键词：Functionalised oligofluorenes ; Suzuki coupling ; Yamamoto coupling ; Photoluminescence
- 刊名：Tetrahedron
- 出版年：2006
- 期刊代码：107_00404020
- 类别：ch
- 出版时间：23 January 2006
- 卷：62
- 期：4
- 页码：627-634
- 文件大小：431 K
摘要
A series of novel bifluorene based systems was synthesised by a convergent approach by means of a Suzuki cross-coupling between 7,7′-bis-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-9,9,9′,9′-tetraoctyl-2,2′-bifluorene and suitable aryl-bromides. All the oligomers have been characterized by 1H, 13C NMR, FT-IR, UV–vis, PL spectroscopy and mass analyses. In particular, it has been demonstrated that the presence of strong electron donor (amines) or withdrawing (carboxylic esters) groups causes a bathochromic shift of the optical properties with respect to those of unsubstituted molecules. The effects of these functional groups on the HOMO–LUMO energy levels were investigated by cyclic voltammetry. Remarkably, the LUMO energy level of 7,7′-bis-[5′-carbodecaoxy-2,2′-bithiophen-5-yl]-9,9,9′,9′-tetraoctyl-2,2′-bifluorene (−3.07 eV) is strongly influenced by the presence of the ester functional group.