Comparative Crystal Field Studies of Some Ligand of Cr3+ Complexes

Author: Azeez Abdullah Azeez Barzinjy^1&2
1Department of Physics, College of Education, Salahaddin University, Erbil, Iraq
²Department of Physics Education, Faculty of Education, Ishik University, Erbil, Iraq

Abstract:   Chromium (III) complexes of nominate ligands are well recognized for their biological significance along with their anti-carcinogenic, anti-bacterial, and anti-fungal properties. In this investigation a range of Cr+3 complexes with diverse ligands were examined; and categorized with ultraviolet-visible, UV-Vis, spectrometer. Crystal field theory is an electrostatic method, utilized to characterize the fragmentation in d-orbital metal energies. It offers an expected explanation of the electronic energy levels that control the UV-Vis spectra. Accordingly, complexes’ crystal field splitting parameters (Δo) are measured through the transition-band using the maximum wavelength. Similarly an additional method, comprising Tanabe-Sugano (TS) diagrams, has been utilized to compute crystal field splitting parameters for assessment. Thus, good agreement was found between both techniques. The configuration of the ligands in increasing order is found to be (H2O) Cl < urea < H2O < OX < NCS < OX H2O < acac < en Cl < NH3 NCS < en which coordinate mostly with the spectro-chemical series. Therefore (H2O) Cl is the weakest ligand, while ethylenediamine (en) is the strongest one among the investigated ligands of Cr3+ complexes. Clearly strong ligands such as; ethylenediamine is considerably influences the coordination geometry of the metal complexes which effect on the deposit morphology and other physical and chemical properties.

Keywords:  Crystal Field Theory, Ligand, Cr+3, UV-Visible Spectrum, Tanabe-Sugano Diagrams

doi: 10.23918/eajse.v3i1sip109

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