Practical Synthesis and Properties of 2,5-Diarylarsoles

2,5-Diarylarsoles
were easily synthesized from nonvolatile arsenic
precursors. Diiodoarsine was generated in situ and reacted with titanacyclo­penta­dienes
to give 2,5-diarylarsoles. The structures and optical properties were
studied in comparison with those of 2,5-diarylphosphole. It was found
that the arsoles were much more stable in the air than the phosphole.
Single crystal X-ray diffraction revealed the arsenic atoms adopted
a trigonal pyramidal structure, reflecting on the s-character of the
lone pair. The obtained 2,5-diarylarsoles and 2,5-diarylphosphole
showed intense emission in solutions and solid state. In addition,
the optical properties were controlled by transition-metal coordination.

2,5-二碘代亚砜从挥发性砷前体中易于合成。现场合成了二碘代砷，并与钛环戊二烯反应得到2,5-二碘代亚砜。其结构与光学性质与2,5-二芳基磷杂茂进行了比较研究。研究发现，亚砜在空气中的稳定性远高于磷杂茂。单晶X射线衍射揭示了砷原子采用了三角锥形结构，反映了孤对电子的s轨道特性。所获得的2,5-二碘代亚砜和2,5-二芳基磷杂茂在溶液和固态中均表现出强烈的发射。此外，其光学性质受过渡金属配位作用控制。