Department of Chemistry and Technology of Functional Materials, Faculty of Chemistry, Gdańsk University of Technology, Narutowicza Street 11/12, 80-233, Gdańsk, Poland.
Advanced Materials Center, Faculty of Chemistry, Gdańsk University of Technology, Narutowicza Street 11/12, 80-233, Gdańsk, Poland.
Chempluschem. 2023 Jun;88(6):e202300175. doi: 10.1002/cplu.202300175.
New products of photo- and thermal rearrangements of 19-membered azoxybenzocrown with phenyl substituents in benzene rings in the para positions to oligooxyethylene fragments are characterized in this work. The yields of photochemical transformations depend on the solvent. Para-hydroxyazocrown is formed with yields over 50 % in propan-2-ol. Ortho-hydroxyazobenzocrown is obtained with yields up to 70 % in toluene/acetic acid mixture. Macrocyclic Ph-20-ester is obtained in yield 90 % under thermochemical rearrangement conditions. Structure of new hydroxyazobenzocrowns and also atypical product of rearrangements, 20-membered ester, was confirmed by X-ray diffraction analysis. Azophenol quinone-hydrazone tautomeric equilibrium of new hydroxyazobenzocrowns and the influence of metal cations on tautomeric equilibrium was investigated using H NMR and UV-Vis spectroscopy in acetonitrile. The highest value of stability constant (logK 7.25) was obtained for strontium complex of p-hydroxyazobenzocrown. For the first time p-hydroxyazobenzocrown was used as a chromoionophore in the receptor layer of an optical sensor. Comparative analysis with data obtained previously for series 19-membered analogs have shown the influence of the presence of substituents in benzene rings for the course and products distribution of photo and thermal rearrangement. The effect of substituents was also discussed against the tautomeric equilibrium and metal cation complexation properties.
这项工作的特点是对带有对位苯氧基乙撑片段的 19 元偶氮苯并冠醚的光和热重排的新产品进行了研究。光化学转化的产率取决于溶剂。在异丙醇中，生成对羟基偶氮苯并冠醚的产率超过 50%。在甲苯/乙酸混合物中，得到对位羟基偶氮苯并冠醚的产率高达 70%。在热化学重排条件下，得到大环 Ph-20-酯，产率为 90%。通过 X 射线衍射分析证实了新的羟基偶氮苯并冠醚以及重排的典型产物，即 20 元酯的结构。使用 H NMR 和 UV-Vis 光谱法在乙腈中研究了新的羟基偶氮苯并冠醚的偶氮酚醌腙互变异构平衡以及金属阳离子对互变异构平衡的影响。得到了对羟基偶氮苯并冠醚与锶络合物的最高稳定常数（logK 7.25）。首次将对羟基偶氮苯并冠醚用作光学传感器的受体层中的显色离子载体。与以前获得的 19 元类似物系列数据的比较分析表明，苯环上取代基的存在对光和热重排的反应历程和产物分布有影响。还讨论了取代基对互变异构平衡和金属阳离子络合性质的影响。
