Anhydrous molybdenum pentachloride (Mo Cl5) was purchased from Sigma-Aldrich/
Germany. Cobalt chloride hexahydrtae (Co Cl2.6H2O) and lead nitrate (Pb (NO3)2) were
acquired from El-Nasr chemical company/ Egypt. Ammonium carbonate [NH4 (CO3)2] and
ammonia solution (NH4OH 37%) were obtained from Merck/ Germany.