Abstract

Treatment of 1,3-diphenyl-1,3-propanedione 1a with europium (III) chloride in the presence of piperidine results in the halide ligands exchange giving newly piperidinium tetrakis (1,3-diphenyl-1,3-propanedionato)europate(III) complex 2a. The complex was characterized by 1H-NMR, positive FAB-mass, and Elemental Analysis. The exact molecular structure of 2a was determined by single crystal X-ray diffraction with the monoclinic space group Cc (centrosymmetric, No.13). The large cavity sizes of the complex 2a facilitated the inclusion of water and benzene solvate molecules. The other two different crystals 2b, 2c having two water molecules and one benzene moleculewere obtained by the crystallization in different solvents and the exact molecular structures were determined by single crystal X-ray diffraction analysis with space groups P21/n (centrosymmetric, No.14), and P21/n (centrosymmetric, No.14), respectively. The eight coordinate structures of the complexes in the three crystals were slightly different due to the crystal packing and the existence of the solvent molecule(s). The photoluminescence studies indicated that four β-diketone ligands acted as strong antenna ligands and transferred the absorbed energy to europium (III) ion, consequently red luminescence was observed. These strong emissions wereattributed to the 5D0 → 7F2 transition of Europium (III) ions under UV excitation. The photoluminescence spectrum of the three crystals was almost same in solid as well as in solution.

Highlights

  • The luminescent properties europium complexes have been of great interest because of their high luminescence emission efficiency, long fluorescence life time, large stokes shift, sharp emission bands [1] [2] [3]

  • The other two different crystals 2b, 2c having two water molecules and one benzene molecule were obtained by the crystallization in different solvents and the exact molecular structures were determined by single crystal X-ray diffraction analysis with space groups P21/n, and P21/n, respectively

  • Piperidinium [tetrakis(1,3-diphenyl-1,3-propanedionato)europate (III)] complex 2a is obtained in 80% isolated yield from the corresponding ligand 1,3-diphenyl-1,3-propanedione by complexation reaction with europium (III) chloride in the presence of piperidine (Scheme 1)

Read more

Summary

Introduction

The luminescent properties europium complexes have been of great interest because of their high luminescence emission efficiency, long fluorescence life time, large stokes shift, sharp emission bands [1] [2] [3]. Europium (III) complexes with β-diketones possessing aromatics substituents displayed very good to excellent photo luminescent properties. Various Europium (III) complexes with β-diketones were synthesized and evaluated for their photo luminescent properties [8] [9] [10] [11] [12]. In this context, we report the synthesis, structural and spectral properties of the octa-coordinate Europium (III) complex 2a, its two different crystals 2b, 2c having two water, benzene solvent molecules as guest molecules carrying four bidentate β-diketonato ligands having eight aromatic moieties and one piperidinium as a counter cation. We have investigated the structural properties using X-ray analyses

Methods
Results
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call