SUBSTITUTED ALUMINUM AND ZINC QUINOLATES WITH BLUE-SHIFTED ABSORBANCELUMINESCENCE BANDS - SYNTHESIS AND SPECTROSCOPIC, PHOTOLUMINESCENCE, AND ELECTROLUMINESCENCE CHARACTERIZATION/

Two novel lumophores based on aluminum and zinc metallo-8-hydroxyquino lates have been prepared as electroluminescent materials, and their ab sorbance, photoluminescence, and electroluminescence properties compar ed with unsubstituted versions of these same complexes. 8-Hydroxy-5-pi peridinylquinolinesulfonamide (1) was synthesized in order to add an e lectron-withdrawing substituent at the 5-position in 8-hydroxyquinolin e, increasing the solubility of the corresponding metal quinolate comp lexes in nonpolar solvents, and producing a blue-shift in the emission wavelength maximum, relative to complexes formed from the unsubstitut ed compound. The aluminum complex (Al(QS)(3)) and the zinc complex (Zn (QS)(2)) of 1 were compared with the aluminum and zinc complexes of un substituted 8-hydroxyquinoline (AlQ(3) and ZnQ(2)), both as solutions and as pure thin films, or as poly(N-vinylcarbazole) (PVK) thin films doped with the metal quinolates. Ultraviolet photoelectron spectroscop y data are presented to assist in estimating the energies of the highe st occupied molecular orbitals (HOMO) of AlQ(3), ZnQ(2), Al(QS)(3), an d Zn(QS)(2). Electroluminescence data shows that ITQ/Al(QS)(3)-PVK/alu minum and ITO/Zn(QS)(2)-PVK/aluminum devices exhibit good diode-like e lectrical behavior. Electroluminescence spectra mimic the photolumines cence spectra for all complexes.