Dehydro-coupling reaction of fluorene in presence of sulfur
1. School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China; 2. School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou, Jiangsu 221008, China）
Abstract：The dehydro-coupling reaction of fluorene in the presence of sulfur was investigated. The reaction was carried under four temperatures and the reaction mixture was detected by GC - MS. The main coupling product was 9,9′ - bifluorenyl and the second was 9,9′ - bifluorenylene. The reaction mechanism was discussed briefly and considered as a free radical reaction procedure. The main coupling product 9,9′-bifluorenyl was purified and characterized by melting point measuring, NMR, MS and FTIR. The better reaction condition for yielding 9,9′ - bifluorenyl was explored and the optimized conditions were 6 hours under 250 ℃ or 2 hours under 275 ℃ and the molar ratio of fluorene/sulfur as 1 ： 1. Under the above two conditions the yields of 9,9′ - bifluorenyl were to 37.5% and 42.8% respectively, and the selectivities were 66.3% and 63.0% respectively.
2008, Vol. 29 
