基于meso-位置含有S原子的醌式Bisanthene衍生物的合成与性质表征

Synthesis,Characterization of meso-Position Sulfur Embedded Quinoidal Bisanthene

在醌式Bisanthene的meso-位置嵌入杂原子S,然后对其光电性质进行研究。原料9-噻吨酮和劳森试剂反应得到硫酮(Ⅲ),接着和水合肼缩合成酮腙(Ⅳ),其后被氧化得到相应的重氮化合物,该产品直接和Ⅲ通过Barton-Kellogg反应制备环硫化合物Ⅴ,接着被Cu粉还原生成烯烃前体Ⅵ。最后对Ⅵ进行Katz-modified Mallory光关环来合成Ⅰ。由于单边关环产物Ⅶ不具有均苯乙烯类结构骨架,不能进一步发生光关环得到目标产物Ⅰ。化合物Ⅶ和Ⅵ相比,表现出扩展的π体系,自身的最大吸收波长红移105 nm,发射波长红移90 nm。另外,电化学测试表明Ⅶ可以被可逆的氧化为阳离子,且被扩展的π体系所稳定。由此推测,目标产物I具有更大的π体系,更长范围的吸收及发射波长,较低的Eg、更多级的可逆氧化电位。

meso-Positions sulfur embedded quinoidal bisanthene I was attempted to synthesized,and its photoelectronic properties were also to be studied. Thione Ⅲ was prepared from corresponding thioxanthen-9-one via reaction with Lawesson’s reagent followed by the Barton-Kellogg reaction with 9-diazothioxanthene derived from corresponding hydrazine Ⅳ to afford the thioepoxides Ⅴ. The resulting compound Ⅴ was then treated with copper powder to give the desired olefin precursor Ⅵ. Katzmodified Mallory photocyclization was carried out on Ⅵ for the purpose to obtain the target molecule I.Unfortunately,the photocyclization stopped at the partially cyclized intermediate Ⅶ,because of the absence of stilbene structure. Compound Ⅶ showed extended π-conjugation compared with its olefin precursors Ⅵ and exhibited 105 nm and 90 nm red shift of the corresponding absorption and emission maxima. In addition,compound Ⅶ can be oxidized into charged states which are stabilized by the delocalized π-system. Therefore,the target molecule I is expected to have a longer absorption and emission wavelength,a lower Eg,as well as a multistage redox behavior.