Related Experiment Video
Updated: May 17, 2026

A Technical Guide for Performing Spectroscopic Measurements on Metal-Organic Frameworks
Published on: April 28, 2023
Study of photophysical properties of different metal complexes of Alq₃
S A Bhagat1, S B Raut, S J Dhoble
1Kamla Nehru College, Sakkardara Square, Nagpur, 440 009, India.
Abstract:
Different metal complexes of Alq₃ (K(+) , Sr(2+) , Ca(2+) and Mg(2+) ) were synthesized by the precipitation method. The characterization of photoluminescence showed that presence of Mg(2+) ion enhances photoluminescence of Alq₃ phosphor. The emission spectra are observed at 560 nm when excited at a wavelength of 440 nm. The phosphor is excited at a longer wavelength in the blue region of small energy, so that it could be used as lamp phosphor. It is observed that the prepared phosphor AlMgq₅ is more suitable than Alq₃. The ionic radii of K(+) , Sr(2+) , Ca(2+) and Mg(2+) ions are in decreasing order. Therefore, the remarkable properties of AlMgq₅ could be considered as promising materials as opto- or optoelectronic materials.
Related Concept Videos
Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
Complexation Equilibria: Factors Influencing Stability of Complexes
Extraction: Advanced Methods
Metal-Ligand Bonds
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
Complexation Equilibria: The Chelate Effect
