245366-93-2Relevant academic research and scientific papers
Synthesis and Photochromism of Crowned Spirobenzothiapyran: Facilitated Photoisomerization by Cooperative Complexation of Crown Ether and Thiophenolate Moieties with Metal Ions
Tanaka, Mutsuo,Kamada, Kenji,Ando, Hisanori,Kitagaki, Takashi,Shibutani, Yasuhiko,Kimura, Keiichi
, p. 4342 - 4347 (2007/10/03)
Spirobenzothiapyrans bearing monoaza-12-crown-4, -15-crown-5, -18-crown-6, and oligooxyethylene moieties were synthesized, and their photochromism was examined in the presence of cations in acetonitrile. The cation complexation by their crown ether moieties cannot induce thermal isomerization to their corresponding colored merocyanine form, unlike the corresponding spirobenzopyran derivatives. The UV-light-induced isomerization was, however, facilitated by the cation complexation of the crown ether moieties and the affinity of the merocyanine thiophenolate anion to metal ions, especially in the presence of Li+ and Ag+. The presence of Ag+ brought about the most remarkable effect in the facilitation of photoisomerization of the spirobenzothiapyrans and the thermal stability of the colored merocyanine form mainly due to the powerful interaction of the thiophenolate anion with the soft metal ion.
Metal-ion stabilization of photoinduced open colored isomer in crowned spirobenzothiapyran
Tanaka, Mutsuo,Kamada, Kenji,Ando, Hisanori,Kitagaki, Takashi,Shibutani, Yasuhiko,Yajima, Setsuko,Sakamoto, Hidefumi,Kimura, Keiichi
, p. 1453 - 1454 (2007/10/03)
A spirobenzothiapyran derivative bearing a monoaza-12-crown-4 moiety affords significant thermal stability enhancement in the UV light induced colored merocyanine form of its photochromic moiety by metal-ion complexation of its crown ether moiety, although the complexation hardly induces the isomerization without photoirradiation.
