Barium dimeric(citrato)oxovanadium(IV) tetrahydrates Ba-2 [VOcit)](2) . 4H(2)O has been prepared by the reaction of sodium dimeric (citrato)oxovanadium (IV) and barium chloride, Its single crystal was obtained by diffusion method in silica-gel, The complex crystallizes in monoclinic space group P2(1)/n with unit cell parameters: a = 0.989 60(9) nm, b = 0.877 46(5) nm, c = 1.210 75(8) nm, beta = 93.119(7)degrees, Z = 2, R = 0.045 for 1 260 reflections with I greater than or equal to 3 sigma(I). Thermal decomposition shows the barium salt undergoes with three major processes, including dehydration, ligand elimination and formation of mixed oxide as its final step, in which the latter is confirmed as pure phase of barium pyrovanadate by XRD analysis
