Abstrakt

Evaluation of two synthesised triheteropolytungstate

Vishnu Shankar Tiwari, Alok Kumar Thakur, G.S.Tiwari, Rajesh Kumar

The series of polytungstate complex was prepared containing Co2+, Cu2+ and Ni2+ hetero cations inducted into the polytungstateanion [W10O39]-18 by conventional method. The acidic mediumwas kept (pH= 4.5) bymixing appropriate quantities of glacial acetic acid and refluxed for two and half hours. After cooling the refluxed mixture produce bright brown coloured solid residue almost after four days. The residue was washed with moderate concentrated ethanol and dried. The elemental analysis of the residue was performed as mentioned in the text book ofQuantitative ChemicalAnalysis by ‘Vogel’. The percentage analysis of the constituent elements of triheteropolycomplex prepared is characterised on the basis of the I.R. spectrum studies and the thermal analysis. On the basis of above analysis the chemical composition of the two different polytungstate complexeswere assigned asNa2[CuNiW12O39]63.5H2OandNa2[NiCoW12O39]37H2O.TheDTA and TGA curves of the two triheteropolytungstate complex it is observed that the major weight losses were in between 200C to 7000C temperature. The magnetic moment measurement at room temperature of both polytungstates indicate the para-magnetic properties of the products.