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Macrocyclic bis(ureas) as ligands for anion complexation
Two macrocyclic bis(ureas) 1 and 2, both based on diphenylurea, have been synthesized. Compound 1 represents the smaller ring with two ethynylene groups as linkers and 2 the larger ring with two butadiynylene groups. On thermal treatment to 130 °C molecule 1 splits up into two dihydroindoloquinolino...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Beilstein-Institut
2014
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4142877/ https://www.ncbi.nlm.nih.gov/pubmed/25161744 http://dx.doi.org/10.3762/bjoc.10.193 |
Sumario: | Two macrocyclic bis(ureas) 1 and 2, both based on diphenylurea, have been synthesized. Compound 1 represents the smaller ring with two ethynylene groups as linkers and 2 the larger ring with two butadiynylene groups. On thermal treatment to 130 °C molecule 1 splits up into two dihydroindoloquinolinone (3) molecules. Both compounds 1 and 2 form adducts with polar molecules such as dimethyl sulfoxide (DMSO) and dimethylformamide (DMF) and act as complexing agents towards a series of anions (Cl(−), Br(−), I(−), NO(3)(−), HSO(4)(−)). The crystal structures of 3, 2·2DMSO, 2·2DMF, and of the complex NEt(4)[Br·2] have been determined. Quantitative investigations of the complexation equilibria were performed via (1)H NMR titrations. While 1 is a rather weak complexing agent, the large ring of 2 binds anions with association constants up to log K = 7.93 for chloride ions. |
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