Synthesis of bisquaraine dyes. Novel homologues of 1,2-squaraines bearing symmetrical and unsymmetrical structures
作者:Yutaka Hyodo、Hiroyuki Nakazumi、Shigeyuki Yagi、Kazuhisa Nakai
DOI:10.1039/b104059f
日期:2001.11.1
In order to investigate analogous structures of 1,2-squaraine dyes, bisquaraines 1 and 2 are newly prepared as their novel homologues. Symmetrical bisquaraine dye 1, in which the same heterocyclic components are introduced at the 3 and 3′ positions of the bisquaryl skeleton, is obtained by reaction of 4,4′-bi(3-isopropoxycyclobut-3-ene-1,2-dione) 3 with a series of heterocyclic compounds 5. The structure of one of the symmetrical dyes is confirmed by X-ray structural analysis, showing a largely extended π-conjugation system over the whole molecule. The synthesis of unsymmetrical dyes 2, in which different aromatic components are introduced, is established by the reactions of 5
with 3′-monosubstituted bisquarates 6. Each bisquaraine dye exhibits two absorption maxima separated by 56–75 nm, the lower-energy absorption of which is observed at 653–757 nm.
为了研究1,2-方酸菁染料的类似结构,制备了两种新型同系物——双方酸菁1和2。通过对4,4'-双(3-异丙氧基环丁-3-烯-1,2-二酮)3与一系列杂环化合物5的反应,得到了在双方酸骨架的3和3'位置引入相同杂环组分的对称双方酸菁染料1。通过X射线结构分析证实了其中一种对称染料的结构,显示整个分子中存在一个延伸的π-共轭体系。非对称染料2的合成通过5与3'-单取代双方酸酯6的反应实现,该染料中引入了不同的芳香组分。每种双方酸菁染料均呈现出两个吸收峰,波长间隔为56-75 nm,其中较低能量的吸收峰位于653-757 nm。