TITLE:
Design, Synthesis, Crystal Structure and Photoluminescence Properties of Four New Europium (III) Complexes with Fluorinated β-Diketone Ligand
AUTHORS:
Tetsuji Moriguchi, Hiromasa Kawata, Venkataprasad Jalli
KEYWORDS:
Tetrakis Europium Complexes, Luminescence, Fluorinate β-Diketone Ligand, Pyridine, Bipyridine, Piperazine, Bipiperidine
JOURNAL NAME:
Crystal Structure Theory and Applications,
Vol.10 No.1,
February
4,
2021
ABSTRACT: The strong
photoluminescence properties of europium complexes with organic ligands
attracted the attention of many researchers and found a wide range of uses in medical, industrial and
biological fields. In this article, four new Tetrakis europium complexes 3a, 3b, 3c and 3d have been prepared using 1-phenyl-4,4,4-trifluoro-1,3-butenedionato
ligand and pyridinium, bipyridinium, piperazinium and piperidinium counter
cations. These complexes have been characterized by negative FAB-mass. The
crystal structures of 3a, 3b, 3c and 3d were
determined by single crystal X-ray diffraction analysis. The complex 3a crystallized in monoclinic form, space group P21/n with four molecules in the unit cell. The
complex 3b crystallized in monoclinic form, space group P2/n with two complex molecules in the unit cell. The complex 3c crystallized in monoclinic form, space group C2/c with sixteen molecules in the unit
cell. The complex 3d crystallized in monoclinic form,
space group P21/n with four complex molecules in the unit cell. The complex 3a has 1,2-alternative structure, 3b has 1,3-alternative structure, 3c has
cone like structure and 3d has partial cone like structure. The
photoluminescence properties of these complexes have been evaluated. Strong red
emissions were observed in all four complexes due to 5D0 → 7F2 transition of Europium (III) ions under UV
excitation. Four β-diketone ligands
acted as strong antenna ligands and transferred the absorbed energy to europium
(III) ion effectively; consequently strong red luminescence was observed.