Author(s)

Tetsuji Moriguchi^1*, Naoya Kitou¹, Daisuke Yakeya¹, Akihiko Tsuge¹, Kenji Yoza², Venkataprasad Jalli³

¹Department of Applied Chemistry, Faculty of Engineering, Kyushu Institute of Technology, Kitakyushu, Japan.
²Japan Bruker AXS K.K., Yokohama, Japan.
³Sankar Foundation, Research and Development Division, Visakhapatnam, India.

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.

Tetrakis Europium Complexes, Luminescence, β-Diketone Ligands

Moriguchi, T. , Kitou, N. , Yakeya, D. , Tsuge, A. , Yoza, K. and Jalli, V. (2017) Syntheses, Crystal Structure and Photoluminescence Properties of Piperidinium Tetrakis (1,3-Diphenyl-1,3-Propanedionato) Europate(III) Complex and Its Two Different Crystals. Crystal Structure Theory and Applications, 6, 57-66. doi: 10.4236/csta.2017.64005.