روشن خوشنوازی

The versatility and accessibility of polyoxornetalates haie led to many recent applications of these conipound in cauilysis and molecular magnetism [I, 2]. The high thermal stability and radiationresisat natute Qt polyoxotungstates in partiular attract attention to the use of these species fir the separation and sequestra4on of radioactive was:es [31. In this ar*le the dioxoiiranium complex is synthesized by self assembly reactior of stioch.iometric ratio of WO, H.AsO and UO and characterized by means of and As NMR, IR and R.aman spectroscopy and elemental analysis. Sitgleline As tiveline W (4:4:424) NMR ,and IR and Raman spectroscopy confirm the aiiiop ha a C, symmetry in sølution and solid states. The stiucture consists of two isWO’ Keggin moieties linked via two symmetrically uranyl groups leading to sandwichtype compiexe. With addition of K or NN cation to the solutIon of the anion, its struetue convert to [ s2WUO] (MNH, K) with ç symmetry 14 These anions are isomer and thee are )wtwen them reversible conergjon with addition1ehiniination of K r NR cation. The anion reacts with Co, Mn, Zn to form metal derivdves in which confIrms that the aflion has a lacunar’ nawre. therefore acts as a ligand. The anion as well as its potassium or animonium gaIt reacts with UO and forms [As2 WUO° aniofl [41, In acidic medium the anioh coverted to H6[AS2W18O62].