of the molecules were synthesized. Bis(3-thienyl)ethene diradicals underwent a reversible photochromic reaction by irradiation with UV and visible light. Photoswitching of intramolecular magnetic interaction was proved by EPR spectroscopy. By choosing an appropriate spacer, the intramolecular exchange interaction in the closed-ring isomer was detected to be more than 150 times larger than that in the
合成了分子两端具有
硝酰基
氮氧自由基的双(3-
噻吩基)-和双(2-
噻吩基)
乙烯。Bis(3-thienyl)ethene diradicals 通过紫外和可见光照射发生可逆的光致变色反应。EPR光谱证明了分子内磁相互作用的光转换。通过选择合适的间隔物,检测到闭环异构体中的分子内交换相互作用比开环异构体大150倍以上。在双(2-
噻吩基)
乙烯双自由基的情况下,光环化反应被禁止,只有在可见光照射下才能发生环化反应。双自由基的闭环异构体由前体的闭环异构体合成。