REACTION MECHANISM OF TRANSITION METAL COMPLEXES-I (UNIT-1).pptx

Chemistry PPT

1. REACTION MECHANISM OF TRANSITION METAL COMPLEXES-I UNIT-1 1 Presented by : Dr. K. NAGARAJ Assistant Professor Institute of Science and Research

2. Complexes in which exchange of one or more ligands are rapidly exchanged are called labile complexes. If the rate of ligand exchange is slow then the complex is said to be inert. Lability is not related to the thermodynamic stability of a complex. A stable complex may be labile or inert , so as the unstable complex . LABILITY AND INERTNESS

3. [Cu(NH 3 ) 4 (H 2 O 2 ) 2 ] 2+ is labile. Its aqueous solution is blue in color. When concentrated hydrochloric acid is added to this solution, the blue solution immediately turns green ,giving [CuCl 4 ] 2- . But when the complex is kept as such it remains as such with out any decomposition ( i.e stable) LABILE AND STABLE COMPLEX

4. [ Co(NH 3 ) 6 ] 3+ reacts slowly. When this complex is treated with concentrated HCl , no reaction takes place. Only when it is heated with 6M HCl for many hours, one NH 3 is substituted by Cl - . [Co(NH 3 ) 6 ] 3+ + HCl [ → Co(NH 3 ) 5 Cl] 2+ + NH 4 + INERT AND UNSTABLE COMPLEX

5. ENERGY PROFILE DIAGRAM : INERT AND LABILE COMPLEX

6. Size of the central metal ion Smaller the size of the metal ion, greater will be the inertness because the ligands are held tightly by the metal ion. Charge on the central metal ion Greater the charge on the metal ion, greater will be the inertness of the complex. Since the M-L bonds are stronger. FACTORS AFFECTING LABILITY OF COMPLEXES

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