Syntheses and Characterization of New Types of uranium–organic COMPOUNDS Containing [uo(2)(NCS)(n)](n-2)n=5 or4

Four new types of uranium–organic compounds, [UO2(NCS)4(bpe)](Hbpe)2 (1),[UO2(NCS)5](Hbpa)3;(2),[UO2(NCS)4(H2O)](Hbpp)2;(3)and[UO2(NCS)5](Hbpmp)(H2bpmp) (4), {bpe =1,2-bis(4-pyridyl)ethane, bpa = 1,2-bs(4-pyridyl)ethane, bpp=1,3-di(4-pyridyl)propane and 4-bpmp=N,N´-bis(4-pyridylmethyl)piperazine)} were prepared from reactions of UO2(NO3)2 with four different organic nitrogen donor-based ligands and potassium thiocyanate under thermalgradient conditions using the branched tube method. All these compounds were structurally characterized by single-crystal X-ray diffraction. The thermal stabilities ofcompounds 14 were studied by thermal gravimetric (TG) and differential thermal analyses (DTA). Solution state luminescent spectra of compounds 1-4 indicate intense fluorescent emissions at ca. 347, 360 and 370 nm, respectively.