Theoretical design of a fluorescence sensor with configuration-transformed metal ion recognition of aza-18-crown-6

• Published in: Supramolecular chemistry Vol. 31; no. 6; pp. 402 - 411
• Main Authors: Li, Zhongliang, Zhang, Ying, Liang, Zhongshuai, Wang, Xueye
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 03.06.2019; Taylor & Francis Ltd
• Subjects: Absorption spectra; Alkaline earth metals; Azacrown ether; Configurations; Coordination compounds; Density functional theory; density functional theory (DFT); Emission spectra; Excitation spectra; Fluorescence; fluorescent chemosensor; functional devices; Ions; Ligands; Metal ions; Sensors; Strong interactions (field theory); time-density functional theory (TD-DFT)
• ISSN: 1061-0278; 1029-0478
• DOI: 10.1080/10610278.2019.1609680

A novel configuration-transformed metal-ion-recognizing fluorescent molecular sensor was designed. The ground state geometries of the free ligand L(L 1 , L 2 )and their metal ion complex L/M n+ have been investigated theoretically by density functional theory (DFT). The interaction of L and a series of alkaline earth metal ions have been carried out by the natural bond orbital (NBO) and mayer bond order. The calculated results reveal that the metal ion Sr 2+  has strong interaction with the free ligand L. The excited states, absorption spectra and fluorescence emission spectra of the free ligands L 1 , L 2  and their complexes L/M n+ were performed by the time-density functional theory (TD-DFT). The UV-vis results show that the absorption peak of L 2 /Sr 2+  has an obvious change compared with that of L 2 , which indicates that the free ligand L 2  can specifically identify the metal ion Sr 2+ . Furthermore, L 2 /Sr 2+  is superior fluorescent molecular sensor compared with other molecules.