Octahedral to Square Planar Transition in Nickel Chelates
Posted on Feb 08 2013
The experiment investigates the equilibrium between the octahedral and square planar geometries in a nickel(II) complexes coordinated by 1,2-bis(3-aminopropylamino)ethane (BAP), a tetradentate ligand containing four nitrogen donors.
The octahedral complex ion [Ni(OH2)2BAP]2+ forms readily in solution with the aqua ligands taking the axial positions. In the formation of the square planar geometry these aqua ligands are removed. In aqueous solution an equilibrium between the two forms is observed:
The equilibrium is shifted using both temperature and electrolyte concetration and is investigated using uv/vis spectroscopy.