Syntheses, structures and fluorescence properties of two Ce/Zn-Ce complexes with an open-chain ether Schiff base ligand

Abstract

Reaction of bis(3-methoxysalicylidene)-3-oxapentane-1,5-diamine (H₂L) with Ce(NO₃)₃ afforded a new Ce(III) complex with composition [Ce(H₂L)(NO₃)₃] (1). Complex 1 reacts with zinc acetate and terephthalic acid to prepare complex 2, [Zn₄Ce₂(L)₄(terephthalate)₂][Ce(DMF)(NO₃)₅]. They have been characterized by elemental analysis, UV/Vis and IR spectroscopy, and single-crystal X-ray diffraction. The structure analysis revealed that 1 is mononuclear, whereas 2 is d-f heteronuclear. The fluorescence properties of the ligand and complexes 1 and 2 were studied in the solid state. The significantly blue-shifted emissions and enhancement of fluorescence in 1 and 2 relative to the ligand were attributed to coordination of ligand with metal ions. The results show that the structure and fluorescence of the Ce(III) complexes can be modified by introducing Zn(II) ion and auxiliary ligand terephthalate.

Keywords:

• Open-chain ether Schiff base ligand
• d-f heteronuclear complex
• crystal structure
• fluorescence property

Additional information

Funding

Project was supported by the Foundation of A Hundred Youth Talents Training Program of Lanzhou Jiaotong University (152022) and Natural Science Foundation of Gansu Province (17JR5RA090).