The coordination chemistry of glutarimide-dioxime(H_(3)A)has been studied related to applications in uranyl sequestration from seawater and for the stabilization of early transition metals in high oxidation states.We ...The coordination chemistry of glutarimide-dioxime(H_(3)A)has been studied related to applications in uranyl sequestration from seawater and for the stabilization of early transition metals in high oxidation states.We report here that the H_(2)A−anion is also suitable for stabilizing Ce(IV)and acts as a tridentate ligand to form the[Ce(H_(2)A)_(3)]^(+)cation.The metal complexes[Ce(H_(2)A)_(3)]Cl and[Ce(H_(2)A)_(3)][BPh_(4)]have been obtained by oxidation of CeIII in the presence of H_(3)A under aerobic conditions.UV-Vis spectroscopy and DFT calculations were performed to characterize the electronic structure and ligand-to-metal charge transfer(LMCT)bands of[CeIV(H_(2)A)_(3)]^(+).X-ray absorption spectroscopy(XAS)was also performed to verify the Ce(IV)oxidation state.Absent a clear electrochemical signal for cerium reduction in[Ce(H_(2)A)_(3)]Cl or[Ce(H_(2)A)_(3)][BPh_(4)]under a range of conditions,DFT calculations predicted a Ce(III/IV)redox couple of−1.22 V vs.Fc/Fc^(+).These results further expand the coordination chemistry of glutarimide-dioxime to tetravalent cerium.展开更多
基金support from the University of Pennsylvania and the U.S.Department of Energy,Office of Science,Office of Basic Energy Sciences,Separation Science program under Award DE-SC0017259National Laboratory was supported by the Director,Office of Science,Office of Basic EnergySciences,Division of Chemical Sciences,Geosciences,and Biosciences Heavy Element Chemistry Program of the U.S.Department of Energy(DOE)at LBNL under Contract No.DE-AC02-05CH11231+2 种基金XANES measurements were performed at beam-line 11-2 at the Stanford Synchrotron Radiation Lightsource,which is supported by the U.S.Department of Energy,Office of Science,Office of Basic Energy Sciences under contract no.DE-AC02-76SF00515We also thank the U.S.Department of Energy,Office of Basic Energy Sciences under award DE-SC0020169 for partial support of E.Lthe Extreme Science and Engineering Discovery Environment(XSEDE),which is supported by NSF(ACI-1548562).
文摘The coordination chemistry of glutarimide-dioxime(H_(3)A)has been studied related to applications in uranyl sequestration from seawater and for the stabilization of early transition metals in high oxidation states.We report here that the H_(2)A−anion is also suitable for stabilizing Ce(IV)and acts as a tridentate ligand to form the[Ce(H_(2)A)_(3)]^(+)cation.The metal complexes[Ce(H_(2)A)_(3)]Cl and[Ce(H_(2)A)_(3)][BPh_(4)]have been obtained by oxidation of CeIII in the presence of H_(3)A under aerobic conditions.UV-Vis spectroscopy and DFT calculations were performed to characterize the electronic structure and ligand-to-metal charge transfer(LMCT)bands of[CeIV(H_(2)A)_(3)]^(+).X-ray absorption spectroscopy(XAS)was also performed to verify the Ce(IV)oxidation state.Absent a clear electrochemical signal for cerium reduction in[Ce(H_(2)A)_(3)]Cl or[Ce(H_(2)A)_(3)][BPh_(4)]under a range of conditions,DFT calculations predicted a Ce(III/IV)redox couple of−1.22 V vs.Fc/Fc^(+).These results further expand the coordination chemistry of glutarimide-dioxime to tetravalent cerium.
