Coordination compounds: The coordination compounds formed

The coordination compounds formed by the transition elements are coloured due to the presence of unpaired electrons that absorb light in their electronic transitions. For example, the complexes containing Iron (II) can exhibit green and pale green colours, but the coordination compounds containing iron (III) have a brown or yellowish-brown colour. When the coordination centre is a metal, the corresponding coordination complexes have a magnetic nature due to the presence of unpaired electrons ... EDTA is used in the treatment of lead poisoning. Some coordination compounds of platinum effectively inhibit the growth of tumours. Examples are: ds-platin and related compounds . (iii) Coordination compounds find use in many qualitative and quantitative chemical analysis. Coordination compounds are those addition molecular compounds which retain their identity in solid state as well as in dissolved state. In these compounds . the central metal atom or ion is linked by ions or molecules with coordinate bonds. e.g., Potassium ferrocyanide, K4 [Fe(CN)6].