1415786-92-3Relevant academic research and scientific papers
Abnormal bromination reaction selectivity of 5-diarylamino-2-methylbenzo[b] thiophene caused by a non-planar conjugated model: Synthesis and theoretical calculation
Wu, Bian-Peng,Pang, Mei-Li,Tan, Ting-Feng,Meng, Ji-Ben
, p. 126 - 132 (2013)
5-Diarylamino-2-methylbenzo[b]thiophene was a new kind of triphenylamine-based charge-transporting material. For further modification of the compounds, bromination selectivity was studied through experiments and molecular simulation using Gaussian 09 program under B3LYP/6-311G (d, p) aided by Gaussian View 05 and Multiwfn Program. The results showed that bromination of 5-diarylamino-2-methyl-benzo[b]thiophene would occurred at an abnormal positions (4- and/or 4′-position) rather than at the normal position (3-position), which was different from those benzo[b]thiophene derivatives with simple 5-substitutes reported in literatures. The abnormal selectivity resulted from a special electron structure in which there was an interfinger-like frontier orbital or a special non-planar conjugated model. Electrons would be donated to the o- and p-positions of linked aromatic rings by this manner of electron delocalization, so that TPA unit rather than thiophene ring became the main factor in the selectivity, and reaction active energy at 4-position was lowest. The results were confirmed by the synthesis of three 4-Br and/or 4′-Br derivatives, compound 4, 5 and 6. Single crystal X-ray diffraction of compound 6 gave conclusive evidence on the abnormal selectivity.
