Speaker
Prof.
Hendrik Vissser
(University of the Free State)
Description
Metal quinolinates are known as key materials in the design of organic light emission diodes (OLEDs). The aluminium complex, tris-(8-hydroxyquinoline) aluminium(III), is the most well-known molecule of this family, although its gallium analogue has also been considered for use in OLEDs [1,2]. Factors that govern the efficacy these metal complexes for potential use in OLEDs include the type of isomer (mer versus fac), inter-molecular interactions (like π-π stacking) and solvento species “trapped” in the crystal lattice. Furthermore it was shown that the emission spectra of these complexes can be red or blue shifted by using derivatives of 8-hydroxyquinoline on the 5 and 7 positions of the ligand backbone with electron withdrawing or donating properties (as in 5,7dichloro-8-hydroxyquinoline (5,7-Cl2Qn) or 5,7 dimethyl-8-hydroxyquinoline (5,7-Me2Qn)) [3-5].
In this work, various complexes of M(Qn)3 (M = Al(III), Ga(III), In(III) and Eu(III); Qn = 8-hydroxyquinoline / 5,7dichloro-8-hydroxyquinoline / 5,7 dimethyl-8-hydroxyquinoline) have been synthesized and characterized with 1H NMR, single crystal X-ray spectroscopy and other means and their photoluminescence properties evaluated [6, 7]. A systematic evaluation of the structural versus luminescence properties of nine M(Qn)3 complexes plus interesting results of two Europium(III) metal complexes are reported here.
3. References
[1] C.W. Tang and S.A. Vanslyke, Appl. Phys. Lett. 51 (1987) 913-915.
[2] P.E. Burrows, L.S. Sapochak, L.S. McCarthy, S.R. Forrest and M.E. Thompson, Appl. Phys. Lett., 64 (1994) 2718.
[3] A. Irfan, R. Cui, J. Zhang and L. Hao, Chem. Phys. 364 (2009) 39-45.
[4] Y. Qin, I. Kiburu, S. Shah and F. Jakle, Org. Lett. 8 (2006) 5227-5230.
[5] Y.W. Shi, M.M. Shi, J.C. Haung, H.Z. Chen, M. Wang, X.D. Liu, Y.G. Ma, H. Xu and B. Yang, Chem. Commun. (2006) 1941-1943.
[6] M. Duvenhage, H.C. Swart, O.M. Ntwaeaborwa and H.G. Visser, Optical Materials, 25 (2013) 2366-2371.
[7] M. Duvenhage, H.G. Visser, O.M. Ntwaeaborwa and H.C. Swart, Physica B, 439 (2014) 46 - 49.
Are you currently a postgraduate student? (Yes/No)
no
Primary author
Prof.
Hendrik Vissser
(University of the Free State)
Co-authors
Dr
Alice Brink
(University of the Free State)
Prof.
Hendrik Swart
(University of the Free State)
Ms
Mart-Mari Duvenhage
(University of the Free State)
Prof.
Odireleng Ntwaeaborwa
(University of the Free State)
