Nanocomposites and nanomaterials

The influence of substituents in ligand molecules on the properties of coordination compounds

Berezhnytska O. 1,2, Rohovtsov O. 1, Savchenko I. 3, Fedorov Ya. 1, 
 Smola S. 4, Trunova O1.
1V.I.Vernadsky Institute of General and Inorganic Chemistry NASU, Kyiv, Ukraine E-mail: olekberez@gmail.com
2National Technical University of Ukraine “Igor Sikorsky Kiev Polytechnic Institute”, Peremohy ave., Kyiv, 3703056, Ukraine 
3National Taras Shevchenko University of Kyiv, Kyiv, Ukraine
4A.V. Bogatsky Physico-Chemical Institute NASU, Odessa, Ukraine

In recent decades, interest in the coordination compounds of lanthanides has been exponential. This is due to both fundamental and applied aspects. The first is associated with the composition, properties and structural features, and the second is with the use of luminescent coordination compounds as precursors of electroluminescent materials in organic LEDs, liquid crystal displays, sensors, molecular thermometers, luminescent labels in biology and analytical chemistry. The addition of various unsaturated substituents into -diketone molecules will make it possible to use them as monomers for polymerization and copolymerization reactions. Variation of substituents in targeted synthesis will allow selecting the optimal ligand systems, which has high values of 4f-luminescence intensity. The Eu3+, Tb3+, Sm3+ complexes based on b-dikenones were synthesized which consist aliphatic and aromatic substitutions in chelate ring 2-methyl-5-phenylpentene-1-dione-3,5, 2-methyl-5- biphenylpentene -1-dione-3,5, 2,6-dymethylheptene-1-dione-3,5, 2,6- dymethylhepten-1-dione-3,5, 2,7-dymethyloktene-1-dione-3,5. On the base of the monomeric complexes the polymeric compounds were synthesized. The complexes composition and the structure of the nearest coordination environment of the metal ion in the complex were determined. It was shown that the ligands are coordinated to c.a. bidentate-cyclic with a delocalized system of -bonds in the chelate ring. All synthesized compounds have intense luminescence in the visible region of the spectrum. The luminescence intensity depends on the electronic structure of the c.i. and the nature of the substituent in the ligand molecule. Higher relative intensity of the luminescence of the complexes containing aromatic substituents, due to the additional antenna effect and high dispersion obtained nanosystems.