Synthesis, characterization, photophysical and computational study of schiff base ligands and their zn(ii) complexes
Loading...
Date
2009
Authors
Eltaher Eltayeb Taha, Naser
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Schiff base ligands and their Zn(II) complexes have shown good potentials in a range
of applications due to their interesting ground and excited state properties. It is
therefore vital to understand how to control the physical and chemical properties of
such compounds in order to be able to tune their photophysical properties according
to application-specific requirements. This dissertation focuses on the synthesis,
characterization and photophysical properties of a variety of Schiff base ligands and
their Zn(II) complexes.
The work was divided into four main parts. In the first part, fourteen Schiff bases
ligands and their Zn(II) complexes were synthesized and fully characterized using
fourier transform infrared spectroscopy (FTIR), elemental analysis, atomic
absorption spectroscopy (AAS) and X-ray single crystal diffractions.
In the second part, the photophysical properties of these compounds were
investigated in both liquid and solid state using ultraviolet visible (UV/Vis) and
fluorescence spectroscopy. Moreover, the thermal properties of the Schiff bases-
Zn(II) complexes were studied using thermographimetric analysis (TGA) and
differential scanning calorimetry (DSC).
In the third part, computational calculations were performed using PM6 and
ZINDO/S at semi-empirical level to study the optical absorption spectra of these
compounds. The computational results give good agreement with the experimental
findings, which indicate the usefulness of these calculations in the design of new
luminescent compounds.
The final part of this work involved attempted fabrication of the organic light
emitting diode (OLED) device. The Schiff base-Zn(II) complex, Zn13, was selected
for OLED device fabrication due to its good luminescence properties and high
solubility in organic solvents. The device was successfully fabricated, but due to its
short lifetime we did not able to measure more of its properties. Further optimization
of the device has to be carried out to enhance its lifetime.
Based on the findings we can suggest that new luminescent materials with desired
color, thermal stability and optical band gap energy could be obtained by synthesis of
specific ligands. It is envisaged that the new Schiff base-Zn(II) materials synthesized
in the present work have potential for application as organic light emitting diodes
(OLED).
Description
PhD
Keywords
Chemical science , Schiff base ligands , Zn(ii) complexes