Coordination of some transition metal ion complexes in choline chloride/tartaric acid room temperature ionic liquid

 Some transition metal chlorides, CrCl3.6H2O, FeClO,CoCl2.6H2O, NiCl2.6H2O and CuCl2.2HO were investigated spectroscopically in the newly prepared choline chloride/ tartaric acid ionic liquid at room temperature. They were found to be soluble as their solubilities were determined by measuring the dissolved metal in ionic liquid by atomic absorption.2The UV-Visible measurements of the transition metal cations of Cr3+, Fe3+, Co2+, Ni2+and Cu2+ showed a complex formation with the above ionic liquid solvent giving an octahedral geometry shape for (Cr)and tetrahedral for the (Fe3+, Co2+, Ni2+and Cu
2+). The solutions were found to be conductive. It was difficult to obtain the result by the infrared measurements because of the viscose nature of this solvent; therefore the complexes are the same as the ionic liquid in measurements.The resultant solutions were also investigated by substitution of solvent ligands by oxalic acid and EDTA salt. The added ligands showed an increase in the absorption energies indicating the occurrence of3.4H23+substitution reaction and weak coordination of the ionic liquid to their metal.Jorgenson rule was used to assist the suggestion of the type of ligands coordinated to transition metal cations. The nature of the bonding between the metal ions and the donor ligands was demonstrated through the Jorgenson rule and calculation of Racah parameters was obtained from appropriate dn  Tanabe-Sugano diagrams together with the qualitative assistance of Orgel diagrams.