Study On Design,Synthesis And Properties Of Anion Receptors Based On Anthryl (Thio)Urea

Anions play important roles in medicine,environmental science,and life science.Therefore,designing novel high selectivity and sensitivity anion receptors received more and more attention.The interaction between anion and receptor mainly includes hydrogen bond,electrostatic force,hydrophobic interaction,and?-?interaction etc.Anthracenyl group is often used as fluorophore for its good fluorescence property.It is well known that thioureas and ureas groups have been used as binding sites in design receptors extensively.The main research works are as follows:?1?Five receptor molecules 1-5 based on anthracene thiourea and urea were designed,synthesized and were characterized by infrared spectroscopy,mass spectrometry,nuclear magnetic resonance spectroscopy and elemental analysis.The chemical sensing properties of receptor molecules 1-5 to anions CN^-,F^-,AcO^-,H₂PO₄^-,Cl^-,Br^-,I^-,HSO₄^-,NO₃^-and the mechanisms were studied by UV-vis titration,fluorescence titration and ¹H NMR titration in dimethyl sulfoxide?DMSO?solution.?2?Receptor molecules 1-3 based on anthracene thiourea were designed.p-Nitrophenylthiosemicarbazide is the anion recognition site for receptor 1,m-nitrophenylthiosemicarbazide is the anion recognition site for receptor 2,o-nitrophenylthiosemicarbazide is the anion recognition site for receptor 3.The experimental results showed that receptor molecules 1-3 can selectively recognize CN^-,F^-,AcO^-in DMSO solution.They bind to CN^-,F^-,AcO^-to a 1:2 complex by-NH in the thiourea group.Because the presence of nitro group makes the identification process have a very obvious color change,naked eye can observe the color change of the solution.Due to the different positions of the nitro groups,the corresponding receptor molecules 1-3have different abilities to recognize anions.?3?Receptor molecules 4-5 based on anthracene urea were designed.p-Nitrophenyl semicarbazide is the anion recognition site for receptor 4,o-Nitrophenyl semicarbazide is the anion recognition site for receptor 5.The experimental results showed that receptor molecules 4-5 have good ability to identify F^-in DMSO solution,and can achieve"naked eye"recognition.In addition,the receptor molecule 5 also showed good fluorescence properties after binding to F^-.