This review aims to provide an overview of the current state of radiation chemistry with respect to the actinide elements,thorium through californium.Despite the inherent radioactivity of the actinides,only a few stud...This review aims to provide an overview of the current state of radiation chemistry with respect to the actinide elements,thorium through californium.Despite the inherent radioactivity of the actinides,only a few studies explore the effects of ionizing radiation on their redox chemistry and surrounding environment.This fundamental knowledge gap,coupled with the current renaissance in actinide-based technologies such as nuclear power,space exploration,and medicine,underscores the importance of research in this interdisciplinary area.This review will focus on the interactions between reactive species formed by radiolysis with actinides and their complexes,offering an inorganic chemist’s perspective on research in radiation chemistry.In addition,a thorough discussion of our current understanding of radiation-induced changes in actinide speciation in both aqueous solution and the solid-state will be provided,focusing on changes in oxidation state distribution,complexation,and secondary coordination effects within inorganic materials.Finally,this review will discuss challenges and opportunities for inorganic chemists to explore this unique intersection of fields.展开更多
Neptunium (Np) possesses a rich and unique chemistry that often diverges from other actinide elements yet remains relatively underexplored compared with the other light actinides.A resurgence of interest in Np has bee...Neptunium (Np) possesses a rich and unique chemistry that often diverges from other actinide elements yet remains relatively underexplored compared with the other light actinides.A resurgence of interest in Np has been spurred by the application of ^(237)Np for plutonium-238 (^(238)Pu) production for use in radioisotope thermoelectric generators (RTGs),necessitating evaluation of Np chemical reactions and materials.The work presented here studied the thermal decomposition of neptunyl ammonium nitrate (NH_(4)NpVIO_(2)(NO_(3))_(3)) for synthesis of neptunium dioxide (NpO_(2)),which is the target material used for production of ^(238)Pu.Additionally,structural characterization of the intermediate solid Np pentoxide (Np_(2)O_(5)) was performed.Advanced solid-state characterization techniques,including simultaneous thermal analysis (STA),powder X-ray diffraction (pXRD),Raman spectroscopy,and density functional theory (DFT) modeling have been combined to study the reaction pathways.Analysis revealed that NH_(4)NpVIO_(2)(NO_(3))_(3) thermally decomposes to a proposed neptunyl nitrate intermediate,followed by Np_(2)O_(5) and finally NpO_(2),all within the temperature range of 150℃-600 ℃.Further characterization of the pentoxide intermediate provided the first Raman spectra of pure-phase Np_(2)O_(5) and associated DFT modeling confirmed Raman peak assignments for this phase.These findings provide mechanistic information to advance production of the critical radioisotope ^(238)Pu and advance the state of knowledge on Np materials chemistry using modern characterization techniques.展开更多
Actinide elements encaged in a superatomic cluster can exhibit unique properties due to their hyperactive valence electrons. Herein, the electronic and spectroscopic properties of Th@Au14 are predicted and compared wi...Actinide elements encaged in a superatomic cluster can exhibit unique properties due to their hyperactive valence electrons. Herein, the electronic and spectroscopic properties of Th@Au14 are predicted and compared with that of the isoelectronic entities [Ac@Au14]- and [Pa@Au14]＋ using density functional theory. The calculation results indicate that these clusters all adopt a closed- shell superatomic 18-electron configuration of the 1S21p61D10 Jellium state. The absorption spectrum of Th@Au14 can be interpreted by the Jelliumatic orbital model. In addition, calculated spectra of pyridine-Th@Au14 complexes in the blue laser band exhibit strong peaks attributable to charge transfer （CT） from the metal to the pyridine molecule. These charge-transfer bands lead to a resonant surface-enhanced Raman scattering （SERS） enhancement of -104. This work suggests a basis for designing and synthesizing SERS substrate materials based on actinide-embedded gold superatom models.展开更多
A monoanionic nitrogen-phosphorus ligand(CH_(3))_(2)NCH_(2)CH_(2)NHPiPr_(2)(L_(3))was designed and the corresponding U(Ⅳ)chloride complex{[(CH_(3))_(2)NCH_(2)CH_(2)NPiPr_(2)]_(2)UCl_(2)}(1)and U(Ⅳ)iodide complex{[(C...A monoanionic nitrogen-phosphorus ligand(CH_(3))_(2)NCH_(2)CH_(2)NHPiPr_(2)(L_(3))was designed and the corresponding U(Ⅳ)chloride complex{[(CH_(3))_(2)NCH_(2)CH_(2)NPiPr_(2)]_(2)UCl_(2)}(1)and U(Ⅳ)iodide complex{[(CH_(3))_(2)NCH_(2)CH_(2)NPiPr_(2)]_(2)UI_(2)}(_(2))were readily synthesized.Complexes 1 and_(2)were fully characterized and the reactivity of complex 1 was further investigated.Complex_(3){[(CH_(3))_(2)NCH_(2)CH_(2)NPiPr_(2)]_(2)U(C1_(2)H_(8))}with a uranium cyclopentadiene unit was constructed by the reaction of 1 with 2,2’-dilithiobiphenyl,which is a rare example of a homoleptic metallafluorene containing an actinide element.展开更多
基金the National Science Foundation Graduate Research Fellowship Program(NSF GRFP-1945994)Forbes was supported by U.S.DOE,Basic Energy Sciences,Heavy Elements Chemistry under award DE-SC0023995+1 种基金Horne was supported by the U.S.DOE,Office of Science,Office of Basic Energy Sciences,Solar Photochemistry Program under award DE-SC0024191LaVerne was supported by the Division of Chemical Sciences,Geosciences and Biosciences,Basic Energy Sciences,Office of Science,US-DOE through Award No.DE-FC02-04ER15533,document number NDRL-5458.
文摘This review aims to provide an overview of the current state of radiation chemistry with respect to the actinide elements,thorium through californium.Despite the inherent radioactivity of the actinides,only a few studies explore the effects of ionizing radiation on their redox chemistry and surrounding environment.This fundamental knowledge gap,coupled with the current renaissance in actinide-based technologies such as nuclear power,space exploration,and medicine,underscores the importance of research in this interdisciplinary area.This review will focus on the interactions between reactive species formed by radiolysis with actinides and their complexes,offering an inorganic chemist’s perspective on research in radiation chemistry.In addition,a thorough discussion of our current understanding of radiation-induced changes in actinide speciation in both aqueous solution and the solid-state will be provided,focusing on changes in oxidation state distribution,complexation,and secondary coordination effects within inorganic materials.Finally,this review will discuss challenges and opportunities for inorganic chemists to explore this unique intersection of fields.
基金supported by the 238Pu Supply Program at the US Department of Energy's Oak Ridge National Laboratory with funding provided by the Science Mission Directorate of the National Aeronautics and Space Administration and administered by the US Department of Energy,Office of Nuclear Energy,under contract DEAC05-00OR22725The authors wish to thank Cory Dryman,John Dyer,Kaara Patton,Curt Porter,and Joseph Renfro for their assistance in preparation and sampling of the 237Np stock used in these experiments.
文摘Neptunium (Np) possesses a rich and unique chemistry that often diverges from other actinide elements yet remains relatively underexplored compared with the other light actinides.A resurgence of interest in Np has been spurred by the application of ^(237)Np for plutonium-238 (^(238)Pu) production for use in radioisotope thermoelectric generators (RTGs),necessitating evaluation of Np chemical reactions and materials.The work presented here studied the thermal decomposition of neptunyl ammonium nitrate (NH_(4)NpVIO_(2)(NO_(3))_(3)) for synthesis of neptunium dioxide (NpO_(2)),which is the target material used for production of ^(238)Pu.Additionally,structural characterization of the intermediate solid Np pentoxide (Np_(2)O_(5)) was performed.Advanced solid-state characterization techniques,including simultaneous thermal analysis (STA),powder X-ray diffraction (pXRD),Raman spectroscopy,and density functional theory (DFT) modeling have been combined to study the reaction pathways.Analysis revealed that NH_(4)NpVIO_(2)(NO_(3))_(3) thermally decomposes to a proposed neptunyl nitrate intermediate,followed by Np_(2)O_(5) and finally NpO_(2),all within the temperature range of 150℃-600 ℃.Further characterization of the pentoxide intermediate provided the first Raman spectra of pure-phase Np_(2)O_(5) and associated DFT modeling confirmed Raman peak assignments for this phase.These findings provide mechanistic information to advance production of the critical radioisotope ^(238)Pu and advance the state of knowledge on Np materials chemistry using modern characterization techniques.
基金Acknowledgements We would like to thank Drs. Jun Liu and Lei Chen for the stimulating discussions. We would also like to acknowledge the support of the National Natural Science Foundation of China （No. 11374004） and the Science and Technology Development Program of Jilin Province of China （No. 20150519021JH）. Z. W. also acknowledges the Fok Ying Tung Education Foundation （No. 142001） and High Performance Computing Center of Jilin University.
文摘Actinide elements encaged in a superatomic cluster can exhibit unique properties due to their hyperactive valence electrons. Herein, the electronic and spectroscopic properties of Th@Au14 are predicted and compared with that of the isoelectronic entities [Ac@Au14]- and [Pa@Au14]＋ using density functional theory. The calculation results indicate that these clusters all adopt a closed- shell superatomic 18-electron configuration of the 1S21p61D10 Jellium state. The absorption spectrum of Th@Au14 can be interpreted by the Jelliumatic orbital model. In addition, calculated spectra of pyridine-Th@Au14 complexes in the blue laser band exhibit strong peaks attributable to charge transfer （CT） from the metal to the pyridine molecule. These charge-transfer bands lead to a resonant surface-enhanced Raman scattering （SERS） enhancement of -104. This work suggests a basis for designing and synthesizing SERS substrate materials based on actinide-embedded gold superatom models.
基金supported by the National Key R&D Program of China(2021YFA1502500)the National Natural Science Foundation of China(No.91961116 and 22271138)+1 种基金the Natural Science Foundation of Jiangsu Province(BK20220065)Programs for High-Level Entrepreneurial and Innovative Talents Introduction of Jiangsu Province.
文摘A monoanionic nitrogen-phosphorus ligand(CH_(3))_(2)NCH_(2)CH_(2)NHPiPr_(2)(L_(3))was designed and the corresponding U(Ⅳ)chloride complex{[(CH_(3))_(2)NCH_(2)CH_(2)NPiPr_(2)]_(2)UCl_(2)}(1)and U(Ⅳ)iodide complex{[(CH_(3))_(2)NCH_(2)CH_(2)NPiPr_(2)]_(2)UI_(2)}(_(2))were readily synthesized.Complexes 1 and_(2)were fully characterized and the reactivity of complex 1 was further investigated.Complex_(3){[(CH_(3))_(2)NCH_(2)CH_(2)NPiPr_(2)]_(2)U(C1_(2)H_(8))}with a uranium cyclopentadiene unit was constructed by the reaction of 1 with 2,2’-dilithiobiphenyl,which is a rare example of a homoleptic metallafluorene containing an actinide element.
