文摘
The first four uranyl peroxide compounds containing ethylenediaminetetra-acetate (EDTA) were synthesized and characterized from aqueous uranyl peroxide nitrate solutions with a pH range of 5鈥?. Raman spectra demonstrated that reaction solutions that crystallized [NaK15[(UO2)8(O2)8(C10H12O10N2)2(C2O4)4]路(H2O)14] (1) and [Li4K6[(UO2)8(O2)6(C10H12O10N2)2(NO3)6]路(H2O)26] (2) contained excess peroxide, and their structures contained oxidized ethylenediaminetetraacetate, EDTAO24鈥?/sup>. The solutions from which [K4[(UO2)4(O2)2(C10H13O8N2)2(IO3)2]路(H2O)16] (3) and LiK3[(UO2)4(O2)2(C10H12O8N2)2(H2O)2]路(H2O)18 (4) crystallized contained no free peroxide, and the structures incorporated intact EDTA4鈥?/sup>. In contrast to the large family of uranyl peroxide cage clusters, coordination of uranyl peroxide units in 1鈥?b>4 by EDTA4鈥?/sup> or EDTAO24鈥?/sup> results in isolated tetramers or dimers of uranyl ions that are bridged by bidentate peroxide groups. Two tetramers are bridged by EDTAO24鈥?/sup> to form octamers in 1 and 2, and dimers of uranyl polyhedra are linked through iodate groups in 3 and EDTA4鈥?/sup> in 4, forming chains in both cases. In each structure the U鈥揙2鈥揢 dihedral angle is strongly bent, at 鈭?40掳, consistent with the configuration of this linkage in cage clusters and other recently reported uranyl peroxides.