An ESIPT Fluorophore Based on Zinc-Induced Intramolecular Proton Transfer between Ligands in the Complex

作者：Zhang, Bin; Gu, Mengsi; Liu, Chunmei; Liu, Xu; Gao, Na; Gao, Qin; Zhu, Yanyan; Tang, Mingsheng; Du, Chenxia^*; Song, Maoping^*

来源：European Journal of Inorganic Chemistry, 2017, 2017(45): 5366-5371.

DOI：10.1002/ejic.201701083

• Proton transfer
• Fluorescence
• Hydrogen bonds
• Zinc

The zinc complex ZnE containing two 2-(2-hydroxyphenyl)-1-ethyl-4-hydroxybenzimidazole (EtL) ligands has been designed and synthesized. The zinc ion acts as a spacer linking the two coordinated EtL, between which intramolecular hydrogen bonds form. Upon excitation, in addition to a weak emission at 399 nm, ZnE exhibits strong excited-state intramolecular proton-transfer (ESIPT) emission with a maximum at 479 nm with a large Stokes shift (8449 cm(-1)) in tetrahydrofuran solution. Importantly, the ESIPT in ZnE also takes place in the powder form, resulting in dual emission (407 and 490 nm) with total photoluminescence quantum yields (phi) of 0.16. The results of quantum calculations suggest that the ESIPT fluorescence is based on a zwitterionic excited-state species resulting from a single proton transfer between the ligands.

• 出版日期2017-12-8
• 单位郑州大学