Chemical and electrochemical synthesis, molecular structures, DFT calculations and optical properties of metal-chelates of 8-(2-tosylaminobenzilideneimino)quinoline

doi:10.1016/j.poly.2015.12.048

Polyhedron

Volume 107, 9 March 2016, Pages 153-162

https://doi.org/10.1016/j.poly.2015.12.048 Get rights and content

Abstract

Bis-chelate complexes with composition ML₂ (M²⁺ = Co, Ni, Cd and Zn) were synthesized on the basis of potential tridentate N, N, O donor Schiff base ligand – 8-(2-tosylaminobenzilideneimino)quinoline (HL) by both chemical (CS) and electrochemical synthesis (ES). CS of zinc complexes leads to obtaining the compounds with composition ZnLCOOCH₃. Structure and properties of the prepared compounds have been studied by means of elemental analysis, IR, ¹H NMR spectroscopy as well as quantum-chemical computations. Electronic spectra of UV–Vis absorption and photoluminescence for cadmium and zinc complexes were studied in acetonitrile solution. Crystal structure of zinc and cadmium complexes was determined by X-ray analysis. In the zinc complex ZnN₆ coordination site was realized due to involving the nitrogen atom of quinoline fragment in coordination to the metal ion. Meanwhile due to X-ray analysis data cadmium complex possesses CdN₆O surroundings with additional coordination of oxygen atom of tosylamino group from one of the ligand. Cobalt and zinc complexes were assigned to have the octahedral structures on the basis of the physical chemical measurements.

Graphical abstract

The metal-chelates with the composition ML₂ (M = Co(II), Ni(II), Cd(II) and Zn(II)) were synthesized and characterized by X-ray, UV–Vis, IR, NMR and luminescent properties. The UV–Vis spectra were detail studied by DFT calculations.

Introduction

Among metal complexes of acyclic azomethine ligands there is special place for chelates of zinc, cadmium and other metals with coordination sites MN₄, MN₂O₂ that were obtained on the basis of Schiff bases (I) derived from 2-hydroxy- or 2-tosylaminobenzaldehydes possessing photo- (PL) and electroluminescent (EL) properties. Zinc and cadmium chelate complexes with azomethine ligands are used as emitting and electron-transport layers for OLED devices [1], [2], [3], [4], [5], [6], [7] due to their synthetic availability, high PL and EL characteristics, high thermal stability, accessibility of vacuum sublimation for obtaining the homogeneous films during production of OLED layers.

Complexes containing quinoline moiety attract great interest despite more than 20 years of history for proposed by Tang and Van Slyke [8] usage of tris-(8-hydroxyquinolinato)aluminum. This compound was firstly used for development of the OLED device working with low voltage [9], [10], [11], [12], [13], [14].

There are well known Schiff base ligands emitting in the blue spectral region such as derivatives of salicylic aldehydes and 2,4-dimethyl-7-aminoquinolines and their zinc complexes [15]. Emission maxima of PL ligands are located in the area λ_PL = 476–524 nm. For zinc complexes these maxima undergoes bathochromic shift and exhibits in the area λ_РL = 503–532 nm. Quantum yields of luminescence for ligands are minor (φ = 0.001–0.005), while they are increasing for complexes up to φ = 0.15.

Complexes of bis{3-methyl-1phenyl-4-[(quinoline-3(or 6)-imino)-methyl]1-H-pyrazol-5-onato}zinc(II) were synthesized [16], [17]. Bis{3-methyl-1-phenyl-4-[(quinoline-3-imino)-methyl]1-H-pyrazol-5-onato}zinc(II) was used to obtain OLED with configuration ITO/Cupc/2-TNTA/Spiro-TPD/Zn complex/BCP/BPhen/LiF/Al emitting in the yellow spectral region (λ_EL = 600 nm) with a luminance of 800 Cd/m² at a voltage of 10 V that corresponds to luminous efficiency of 0.5 Lm/W. For the device with electroluminescent layer of bis{3-methyl-1phenyl-4-[(quinoline-6-imino)-methyl]1-H-pyrazol-5-onato}zinc(II) brightness characteristics are 200 Cd/m² at a voltage of 13 V.

The similar complexes of zinc and cadmium with 3-(or 6)-[2-(N-tosylaminobenzilidene)]aminoquinoline were synthesized [17]. OLED device was produced by using bis{[6-(2-tosylaminobenzilidene)]amino]quinolinato}zinc(II) for an emitting layer. Device emitted yellow light with CIE (x = 0.463, y = 0.484), brightness was 150 Cd/m² at a voltage of 10 V.

Here we report the chemical [20] and electrochemical [21] synthesis of novel cobalt, nickel, zinc and cadmium complexes on the base of 8-(2-tosylaminobenzilideneimino)quinoline aimed for searching new metal-chelates with PL properties as potential materials for OLED [18], [19].

Section snippets

Materials required and general methods

All starting materials and solvents were used as commercial products. 2-Tosylaminobenzaldehyde was prepared as described earlier [22]. C, H, N elemental analysis was performed in the analytical laboratory of Institute of Physical and Organic Chemistry (SFU, Rostov-on-Don, Russia). The metal content was determined gravimetrically.

Infrared spectra were recorded on a «Varian Excalibur-3100» FT-IR spectrophotometer by attenuated total internal reflection technique.

NMR ¹H spectra were measured on a

Results and discussion

As it was shown previously [10], [18] for complexes СuL₂ the reaction between the potentially tridentate azomethine I (LH, X = NTs) and copper(II) acetate dehydrate leads to mononuclear CuLCOOCH₃ complex (IIIа) preserving acetate group instead of expected bis-chelate II (Scheme 1). Bis-chelate CuL₂ complexes (II) are obtained in the case of ES.

All complexes II synthesized by CS and ES methods possess ML₂ composition due to elemental analysis. The only exception is zinc complex IIIb obtained by CS

Conclusion

Thus, the present results and the data [17] show that the implementation of different composition and structure of the metal complexes depend on the position of the amino group (3, 6 or 8) in the quinoline moiety of azomethine I, the nature of the metal and the method of synthesis. Five-coordinated chelate complexes of copper(II) CuL₂ and CuLCOOCH₃ [18] were synthesized from potentially tri-dentate ligand – 8-(2-tosylaminobenzilideneimino)quinoline. Chemical synthesis from metal acetates leads

Acknowledgements

IR and NMR spectra were obtained using facilities of the “Molecular Spectroscopy” Multi-user Center of the Southern Federal University. This work was performed in the framework of the Project Part of the State Assignment in Academic Areas (Project No. 4.742.2014/K).

References (32)

L. Chen et al.
Inorg. Chim. Acta
(2009)
J. Xie et al.
Inorg. Chim. Acta
(2005)
H. Xu et al.
Polyhedron
(2007)
Q. Su et al.
Polyhedron
(2007)
A.P. Pivovarov et al.
Russ. Chem. Bull.
(2002)
M.G. Kaplunov et al.
Russ. Chem. Bull.
(2004)
A.S. Burlov et al.
Electroluminescent Organic Light-Emitting Diodes Based Metal Coordination Compounds
(2015)
A.S. Burlov et al.
Russ. Chem. Bull.
(2014)
A.S. Burlov et al.
Russ. Chem. Bull.
(2014)
C.W. Tang et al.
Appl. Phys. Lett.
(1987)

B.I. Kharisov et al.

J. Coord. Chem.

(2007)

B. Chiari et al.

Inorg. Chem.

(1989)

K. Takahashi et al.

J. Am. Chem. Soc.

(2008)

C. Dias et al.

Inorg. Chim. Acta

(2007)

F. Tisato et al.

J. Chem. Soc., Dalton Trans.

(1990)

V.I. Minkin, A.Yu. Tsivandze, A.S. Burlov, A.V. Vannikov, E.I. Mal’tsev, A.V. Dmitriev, D.A. Lypenko, S.I. Pozin, A.I....

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Chemical and electrochemical synthesis, molecular structures, DFT calculations and optical properties of metal-chelates of 8-(2-tosylaminobenzilideneimino)quinoline

Abstract

Graphical abstract

Introduction

Section snippets

Materials required and general methods

Results and discussion

Conclusion

Acknowledgements

Inorg. Chim. Acta

Inorg. Chim. Acta

Polyhedron

Polyhedron

Russ. Chem. Bull.

Russ. Chem. Bull.

Electroluminescent Organic Light-Emitting Diodes Based Metal Coordination Compounds

Russ. Chem. Bull.

Russ. Chem. Bull.

Appl. Phys. Lett.

J. Coord. Chem.

Inorg. Chem.

J. Am. Chem. Soc.

Inorg. Chim. Acta

J. Chem. Soc., Dalton Trans.