95-34-1Relevant articles and documents
Thermally Induced trans-to-cis Isomerization and Its Photoinduced Reversal Monitored using Absorption and Luminescence: Cooperative Effect of Metal Coordination and Steric Substituent
Zhang, Jun-Quan,Zhang, De-Shan,Chen, Qiu-Jie,Xu, Hai-Bing,Kurmoo, Mohamedally,Zeng, Ming-Hua
, p. 5177 - 5185 (2019/03/17)
For ethene derivatives with large groups the cis-isomer is often quite unstable and unavailable. Herein, we report an exception of two stable coordination complexes, (cis-L)ZnCl2, starting from trans-1,2-bis(1-R-benzo[d]imidazol-2-yl)ethene (R=H, L1; R=CH3, L2) ligands under solvothermal condition (T ≥140 °C). Using the intensity of the absorption and luminescence spectra as probes we proposed its progressive cis-to-trans reversal upon irradiation with UV light, which was confirmed by powder X-ray diffraction (PXRD). Similar results observed in the series of (cis-L2)MIICl2 [M=Fe (4), Co (5), Ni (6)] demonstrate the universal strategy. The results of PXRD, NMR spectroscopy, ESI-MS and DFT calculations support the above conclusion. NMR spectroscopy indicates that irradiation of 1 converts an optimized 71 % of the cis-isomer to trans, whereas the free trans-L1 ligand transforms to only 15 % cis-isomer under similar conditions.
A Simple Synthesis of 2,2'-Bisbenzimidazolylethylen And Its Analogues
Dash, Bhabagrahi,Dora, Essilidi K.,Panda, Chandra S.
, p. 697 - 698 (2007/10/02)
o-Aminomaleanilic acid (IIa) has been conveniently prepared and employed as a novel synthon for one-step synthesis of 2,2'-bisbenzimidazolylethylene (IIIa) in polyphosphoric acid medium.Analogous compounds (IIIb-f)have also been synthesized from o-hydroxy- and o-mercaptomaleanilic acids (IIb and IIc) following a similar procedure.
