Synthesis, structure, photo- and electroluminescent properties of zinc (II) complexes with aminomethylene derivatives of 1-phenyl-3- methyl-4-formylpyrazol-5-one and 3- and 6-aminoquinolines Anatolii S. Burlov a , Valery G. Vlasenko b , Artem V. Dmitriev c , Vasilii V. Chesnokov a , Ali I. Uraev a , Dmitrii A. Garnovskii a, d , Yan V. Zubavichus e, f , Alexander L. Trigub e , Igor S. Vasilchenko a, *, Dmitrii A. Lypenko c , Eugenii I. Mal’tsev c , Tat’yana V. Lifintseva g , Gennadii S. Borodkin a a Institute of Physical and Organic Chemistry of Southern Federal University, Stachki ave. 194/2, Rostov-on-Don, Russian Federation b Institute of Physics of Southern Federal University, Stachki ave. 194, Rostov-on-Don, Russian Federation c A.N. Frumkin Institute of Physical Chemistry and Electrochemistry of RAS, Leninskii ave. 31/4, Moscow 119991, Russian Federation d Southern Scientific Centre of Russian Academy of Sciences, Chekhova ave. 41, Rostov-on-Don Russian Federation e National Research Centre “Kurchatov Institute”, Academician Kurchatov sq. 1, Moscow 123182, Russian Federation f A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova str. 28, Moscow 119991, Russian Federation g Southern Federal University, Sadovaya str. 105/42, Rostov-on-Don 344006, Russian Federation A R T I C L E I N F O Article history: Received 24 June 2014 Received in revised form 11 February 2015 Accepted 17 February 2015 Available online xxx Keywords: Azomethines Luminescence DFT computation XAFS LED A B S T R A C T Quinolyl-3-pyrazole (I) and quinolyl-6-pyrazole (II) azomethines have been used as precursors to novel zinc complexes (III,IV, correspondingly) that have been synthesized and thoroughly investigated by IR, UV–vis, NMR 1 H spectroscopy. The atomic structure of the complexes was determined by quantum- chemical calculations (DFT-optimization of the molecules geometry). The results obtained were compared with quantitative characteristics of the local atomic environment of zinc ions derived from Zn K-edge EXAFS. Theoretical and experimental data on the bond lengths within the metal coordination sites are in a good agreement. Bands in experimental UV–vis spectra have been assigned based on computational results. Photo- and electroluminescent properties of zinc complexes have been investigated. The photoluminescence maximum occurs around l = 478 nm for both compounds. Prototypes of electroluminescent devices utilizing the complexes as active media were designed and tested. The device with III as the electroluminescent layer shows a luminance of 800 Cd/m 2 at 10 V with conversion efficiency of 0.5 Lm/W, whereas the device with IV as the electroluminescent layer demonstrates somewhat lower characteristics, viz., 200 Cd/m 2 at 13 V. ã 2015 Elsevier B.V. All rights reserved. 1. Introduction Zinc complexes of azomethine ligands are the matter of interest as active layers for OLED devices owing to their thermal stability, and high vitrification temperatures, easy sublimation during deposition of thin amorphous films, variability of structures, relative synthetic affordability, promising photo- (PL) and electro- luminescent (EL) properties and electron-transfer characteristics. PL and EL properties of zinc complexes on the base of bidentate [1–7], tetradentate [8–14] azomethine ligands, including 2- hydroxy- and 2-tosylaminobenzaldehyde derivatives [15–18], were widely studied. The varying the substituents in amino and aldehyde moieties in molecule of zinc complexes of bidentate azomethine ligands derived from 2-hydroxybenzaldehyde and aryl(alkyl) amines allows the regulation of the position of the long wavelength absorption band maxima in the UV spectra and the maxima of emission bands in UV and EL spectra. In the zinc bis(2-hydroxybenzaldiminates) series, the long wavelength absorption band maximum in the UV spectra is observed at l abs = 400–412 nm [19]. The PL band maxima of complexes are in the range l PL = 480–553 nm. Both the absorption spectra and the PL spectra tend to undergo a bathochromic shift * Corresponding author. Tel.: +7 8632434776. E-mail address: vas@ipoc.sfedu.ru (I.S. Vasilchenko). http://dx.doi.org/10.1016/j.synthmet.2015.02.028 0379-6779/ ã 2015 Elsevier B.V. All rights reserved. Synthetic Metals 203 (2015) 156–163 Contents lists available at ScienceDirect Synthetic Metals journal homepage: www.else vie r.com/locat e/synme t