Preparation and properties and spectral studies of metal complexes of picramic acid

Picric Acid is versatile organic compound used for variety of purposes like explosive, yellow dye for woolen fabrics etc. It can be used to prepare amino-derivatives like 2-amino-4, 6 dinitro pheonol ; 2,4-Diamino-6-nitrophenol and 2,4,6-Trinitrophenol etc. Picramic Acid is 2-Amino- 4,6-dinitrophenol which has been used to prepare some compounds. Picramic acid contains one –OH group at one position and one -NH2 group at either at 2-position and the remaining 4-position and 6-position or 2-position and 6-position are occupied by -NO2 groups ,-NH2 groups contains lone pair of electron and - OH group is acidic and can be deprotonated. Picramic acid was prepared by following the method given by Grete Egerer. A pure sample of picric acid was obtained by crystallization from hot water in alcohol and then solution was made alkaline by NH4OH. Temperature was maintained around 300C. Washed H2S gas was passed in the solution and at this stage temperature was maintained around 50-550centigrade.Crystals of ammonium salts of picramic acid was decomposed with (1:4) acetic acid and water mixture . The crystals were collected and recrystallised from hot water. Complexes with Cobalt were obtained by refluxing alcoholic solution of picramic acid and anhydrous CoCl2 and [Co(NH3)6]Cl3 respectively .