Synthesis and optoelectronic properties of three Eu(III)-dipicolinate complexes based on α-picolinic acid, 2-aminopyridine and 2-hydroxypyridine as secondary ligands



We synthesized some Eu(III) complexes {[Eu(dpa)(α-pc)(CH3OH)]·2CH3OH} (1), {[Eu(dpa)(2-ap)(CH3OH)]·2CH3OH}(2) and {[Eu(dpa)(2-hp)(CH3OH)]·2CH3OH}(3) [dpa = dipicolinic acid; α-pc = α-picolinic acid; 2-ap = 2-aminopyridine; 2-hp = 2-hydroxypyridine]. The structural characterization of the complexes were studied by elemental analysis, FTIR spectroscopy, SEM and powder X-ray diffraction studies (XRD) where the elemental analysis and FTIR results indicate the coordination of ligands with the Eu(III) ion. The X-ray diffraction patterns show the crystalline nature of complex (1) and amorphous nature of complexes (2) and (3) and the SEM micrographs also depict different morphologies of the complexes. The thermal properties of the synthesized complexes were studied by TG–DTA technique which indicates good thermal stability of the synthesized complexes. The optical properties were studied using Ultraviolet visible spectroscopy (UV–Vis) and Photoluminescence studies (PL) where photoluminescence measurements indicate that all the three complexes exhibit the characteristic emission bands of Eu(III) ion corresponding to 5Do → 7FJ (J = 0–4) transitions and it has also been observed that the intensity of emission is influenced by the effect of different secondary ligands. The most intense transition and the long radiative lifetime, quantum efficiency of the 5Do excited level of Eu(III) ion observed for the complex (2) with 2-ap as secondary ligand reflects the good sensitizing ability of ligand 2-ap. The optical properties of the obtained complexes can be well utilized for preparation of rare earth luminescent materials and fluorescence probes.


Dipicolinic Acid EuCl3 Europium Complex Secondary Ligand Characteristic Emission Band 
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The authors would like to thank Guru Gobind Singh Indraprastha University, New Delhi for providing financial support as Indraprastha Research Fellowship for research work.


  1. 1.
    J.H. Xue, X.H. Hua, L.M. Yang, W.H. Li, Y.Z. Xu, G.Z. Zhao, G.H. Zhang, K.X. Liu, J.E. Chen, J.G. Wu, Synthesis, crystal structures and luminescence properties of europium and terbium picolinamide complexes. Chin. Chem. Lett. 25, 887–891 (2014)Google Scholar
  2. 2.
    L. Meijuan, W. Xiaoping, T. Qiang, L. Qidan, Luminescence properties of polymers containing europium complexes with 4-tert-butylbenzoic acid. J. Rare Earths 31, 950–956 (2013)CrossRefGoogle Scholar
  3. 3.
    K.P. Zhuravlev, V.I. Tsaryuk, I.S. Pekareva, J. Sokolnicki, Z.S. Klemenkova, Europium and terbium ortho-, meta-, and para-methoxybenzoates: Structural peculiarities, luminescence, and energy transfer. J. Photochem. Photobiol. A 219(219), 139–147 (2011)CrossRefGoogle Scholar
  4. 4.
    M. Rasanen, H. Takalo, J. Rosenberg, J. Makela, K. Haapakka, J. Kankare, Study on photophysical properties of Eu(III) complexes with aromatic β-diketones—Role of charge transfer states in the energy migration. J. Lumin. 146, 211–217 (2014)CrossRefGoogle Scholar
  5. 5.
    M.G. Lahoud, L.F. Marques, P.B. Da Silva, C.A. De Jesus, C.C. Da Silva, J. Ellena, R.S. Freits, M.R. Davolos, C.G. Frem Regima, Synthesis, crystal structure and photoluminescence of a binuclear complex of europium(III) containing 3,5-dicarboxypyrazolate and succinate. Polyhedron 54(54), 1–7 (2013)CrossRefGoogle Scholar
  6. 6.
    G. Zucchi, O. Maury, P. Thurey, M. Ephritikhine, Structural diversity in Neodimium bipyrimidine compounds with near infrared luminescence: From mono and binuclear complexes to metal-organic frameworks. Inorg. Chem. 47, 10398–10406 (2008)CrossRefGoogle Scholar
  7. 7.
    L. Armelao, S. Quici, G.A. Barigelletti, G. Bottaro, M. Cavazzini, E. Tondello, Design of luminescent lanthanide complexes : From molecules to highly efficient photo-emitting materials. Coord. Chem. Rev. 254, 487–505 (2010)CrossRefGoogle Scholar
  8. 8.
    G.F. De Sa, O.L. Malta, C. de Mello Donega, A.M. Simas, R.L. Longo, P.A. Santacruz, E.F. Da Silva Jr., Spectroscopic properties and design of highly luminescent lanthanide coordination complexes. Coord. Chem. Rev. 196, 165–195 (2000)CrossRefGoogle Scholar
  9. 9.
    H.A. Azab, A. Duerko, Z.M. Anwar, B.H.M. Hussein, M.A. Rizk, Luminescence recognition of different organophosphorus pesticides by the luminescent Eu(III)-pyridine-2,6-dicarboxylic acid probe. Anal. Chim. Acta 759, 81–91 (2013)CrossRefGoogle Scholar
  10. 10.
    H. Zheng, D. Gao, F. Zhenxing, E. Wang, Y. Lei, Y. Tuan, M. Cui, Fluorescence enhancement of Ln3+ doped nanoparticles. J. Lumin. 131, 423–428 (2011)CrossRefGoogle Scholar
  11. 11.
    L. Zhang, Y. An, W. Ahmad, Y. Zhou, Z. Shi, X. Zheng, A new quarternary luminescence enhancement system of Eu-N-(3-methoxysalicylidene)-2-aminopyridine-1,10-phenanthroline-Zn and its application in determining trace amounts of Eu3+ and Zn2+. J. Photochem. Photobiol. A 252, 167–173 (2013)CrossRefGoogle Scholar
  12. 12.
    Z. Hnatejko, G. Dutkiewicz, M. Kubicki, S. Lis, New complexes of cobalt(II) ions with pyridine carboxylic acid N-oxides and 4,4′-byp. J. Mol. Struct. 1034, 128–133 (2013)CrossRefGoogle Scholar
  13. 13.
    G.X. Liu, Y.Y. Xu, X.M. Ren, S. Nishihara, R.Y. Huang, Self–assembly of 3d-4f coordination frameworks based on pyridine-3,5-dicarboxylic acid: Synthesis, crystal structuresand luminescence. Inorg. Chim. Acta 363, 3727–3732 (2010)CrossRefGoogle Scholar
  14. 14.
    R. Tang, Q. Zhao, Z.E. Yan, Y.M. Luo, Synthesis of novel derivatives of pyridine-2,6-dicarboxylic acid. Synth. Commun. 36, 2027–2034 (2006)CrossRefGoogle Scholar
  15. 15.
    Q. Yue, J. Yang, G.H. Li, G.D. Li, W. Xu, J.S. Chen, S.N. Wang, Three dimensional 3d-4f Heterometallic coordination polymers: Synthesis. Struct. Magn. Prop. Inorg. Chem. 44, 5241–5246 (2005)CrossRefGoogle Scholar
  16. 16.
    J.C.G. Bunzli, Lanthanide Luminescence for biomedical analyses and imaging. Chem. Rev. 110, 2729–2755 (2010)CrossRefGoogle Scholar
  17. 17.
    H. Tsukube, S. Shinoda, Lanthanide complexes in molecular recognition and chirality sensing of biological substrates. Chem. Rev. 102, 2389–2403 (2002)CrossRefGoogle Scholar
  18. 18.
    D.T. De Lill, D.A. Bettencourt, C.L. Cahill, Exploring Lanthanide luminescence in Metal-Organic Frameworks: Synthesis, Structure and Guest-Sensitized Luminescence of a mixed Europium/Terbium-Adipate Framework and a Terbium-Adipate Framework. Inorg. Chem. 46, 3960–3965 (2007)CrossRefGoogle Scholar
  19. 19.
    D. Ma, W. Wang, Y. Li, J. Li, C. Daiguebonne, G. Calvez, O. Guillou, In situ 2,5-pyrazinedicarboxylate and oxalate ligands synthesis leading to a microporous europium-organic framework capable of selective sensing of small molecules. Cryst. Eng. Comm. 12, 4372–4377 (2010)CrossRefGoogle Scholar
  20. 20.
    J. Huang, Y. Xu, X. Chen, D. Xu, Y. Xu, Q. He, Synthesis, characterization and properties of some rare earth complexes with 2,6-pyridine dicarboxylic acid and α-Picolinic acid. J. Rare Earths 30, 586–591 (2012)CrossRefGoogle Scholar
  21. 21.
    S. Mistri, E. Zangrando, S.C. Manna, Cu(II) complexes of pyridine-2,6-dicarboxylate and N-donor neutral ligands: Synthesis, crystal structure, thermal behavior, DFT calculation and effect of aromatic compounds on their fluorescence. Inorg. Chim. Acta 405, 331–338 (2013)CrossRefGoogle Scholar
  22. 22.
    S.P. Jose, S. Mohan, Vibrational spectra and normal co-ordinate analysis of 2-aminopyridine and 2-aminopicoline. Spectrochimica. Acta. Part A. 64, 240–245 (2006)CrossRefGoogle Scholar
  23. 23.
    D. Wang, Y. Pi, C. Zheng, L. Fan, Y. Hu, X. Wei, Preparation and photoluminescence of some europium (III) ternary complexes with β-diketone and nitrogen heterocyclic ligands. J. Alloy. Compd. 574, 54–58 (2013)CrossRefGoogle Scholar
  24. 24.
    R. Lyszczek, L. Mazur, Polynuclear complexes constructed by lanthanides and pyridine-3,5-dicarboxylate ligand: Structures, thermal and luminescent properties. Polyhedron 41, 7–19 (2012)CrossRefGoogle Scholar
  25. 25.
    M.E. Mesquita, S.S. Nobre, M. Fernandes, R.A.S. Ferreira, S.C.G. Santos, M.O. Rodrigues, L.D. Carlos, V. de Zea Bermudes, Highly luminescent di-ureasil hybrid doped with a Eu(III) complex including dipicolinate ligands. J. Photochem. Photobiol. A 205, 156–160 (2009)CrossRefGoogle Scholar
  26. 26.
    M.R. George, C.A. Golden, M.C. Grossel, R.J. Curry, Modified dipicolinic acid ligands for sensitization of Europium(III) luminescence. Inorg. Chem. 45, 1739–1744 (2006)CrossRefGoogle Scholar
  27. 27.
    A.A. Picot, P.L. Baldeck, C. Andraud, O. Maury, Design of dipicolinic acid ligands for the two-photon sensitized luminescence of europium complexes with optimized cross- sections. Inorg. Chem. 47, 10269–10279 (2008)CrossRefGoogle Scholar

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© Springer Science+Business Media New York 2014

Authors and Affiliations

  1. 1.University School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha UniversityNew DelhiIndia

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