电子反常供需型Diels-Alder反应(inverse electron demabd Diels-Alder reaction,IDA)因其在天然生物碱及类似物合成中的应用,在近20年来已经逐渐引起关注[1].含氮芳杂环体系1,2,4-三嗪由于其特有的缺电子特征,作为双烯体非常适于进行这类反应[2].本文利用IDA反应从3-吡啶基-5,6-二取代-1,2,4-三嗪出发,设计出一条简捷、低成本的合成路线,成功地合成出不对称取代的2,3′-联吡啶和2,4′-联吡啶.这一类化合物已被应用于药物中间体或有机配体.……
A new chiral conjugated polymer was synthesized by the Wittig-Horner polymerization of optically active binaphthyl monomer at the 3,3-positions. The circular dichroism spectrum of the polymer shows that the degree of circular polarization in absorption, g_ abs, is 1.9×10 -3 in chloroform at room temperature. The circularly polarized photoluminescence spectrum of the polymer shows that the degree of circular polarization in emission, g_ lum, is -1.6×10 -3 in chloroform at room temperature. As the polymer is readily soluble in chloroform, the results indicate that the circular polarization in absorption and emission is originated from molecularly dissolved chains and is due to exciton coupling between chain segments of the same polymer molecule. The results also show that the polymer could emit partially circularly polarized light when irradiated in chloroform at room temperature.
A novel chiral conjugated polymer with chiral 1,1-binaphthyl and 2,2-bipyridyl units was prepared. The ion responsive properties of the polymer were measured in tetrahydrogenfuran by using absorption, emission spectra and optical rotation. The results show that absorption, emission spectra and optical rotation of the polymer solutions have different responses with interactions of different transition metal ions. The mechanism is that different changes of electrical and steric effects of the polymer can cause different changes of the properties of the polymer when interacting with different transition metal ions. The novel chiral polymer could be used for metal ion sensing.
