Determination of stoichiometries and stability constants of chromium complexes with some nitrogen-containing ligands
Determination of stoichiometries and stability constants of chromium complexes with some nitrogen-containing ligands
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Date
2015-06-14
Authors
Abdalazeem Abdeen, Omar
Journal Title
Journal ISSN
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Publisher
University of Khartoum
Abstract
The work outlined in this thesis includes the preparation and
analyzation of Cr3+ with two nitrogen-containing ligands ,
ethanolamine and diethylamine , for determination of
stiochiometries and stability constants of the chelates and the
factors that effect the formation of the chelates such as
temperature,pH and time .The dissociation constants of the
ligands were calculated and compared with that recoreded in
literature .
Two methods were adopted the pH-metric method and
spectrophotometric method .
The result is that ethanolamine formed chelates 1:1 and 1:3 with
Cr3+ ion and the study have been done with two above methods
,the stability constants was in order K1< K3 , that indicates
chelate 1:3 is more stable than chelate 1:1 .
Diethylamine ligand with Cr3+ ion formed complexes 1:2 and
1:3 , the stability constants for complexes were calculated by
pH-metric method and spectrophotometric method , the result
found is in the order K2 < K3 , what indicates complex 1:3 is
stabler than complex 1:2 .
The study shows that he stability constant ( K3) for diethyamine
chelate with Cr3+ is greater than ( K3) for ethanolamine chelate
with Cr3+ for diethylamine is more alkaline than ethanolamine .
In this task the effect of some external factors such as pH ,
temperature and the time have been studied and the influence of
these parameters has been recorded .
Description
123 Pages
Keywords
containing ligands,
stoichiometries,
chromium complexes