Lanthanide complexes of a steroid-substituted benzocrown ether were synthesised. The metal-to-ligand ratio of all the metal complexes is 1∶1. The ligand 4′-[(cholesteryloxy)carbonyl]-benzo-15-crown-5 is a monotropic...Lanthanide complexes of a steroid-substituted benzocrown ether were synthesised. The metal-to-ligand ratio of all the metal complexes is 1∶1. The ligand 4′-[(cholesteryloxy)carbonyl]-benzo-15-crown-5 is a monotropic liquid crystal, displaying a cholesteric mesophase. The lanthanide complexes with nitrate counter-ions form a highly viscous mesophase, decomposing at the clearing point. The transition temperatures change as a function of the lanthanide ion. The corresponding lanthanide complexes with dodecylsulphate (DOS) counter-ions do not form a mesophase. In both cases, the metal complexes have a much lower melting point than the parent ligand.展开更多
X-ray detection and imaging via scintillators has been utilized in missions worldwide within areas of scientific research,medical industry,military defense and homeland security.Commercial scintillators are costly wit...X-ray detection and imaging via scintillators has been utilized in missions worldwide within areas of scientific research,medical industry,military defense and homeland security.Commercial scintillators are costly with high energy consumption through the sintering.It is of great significance to seek alternative scintillating materials for sensitive X-ray detection in the next-generation.Herein,eight structure-defined Ln(Ⅲ)-based metal-organic frameworks(Ln-MOFs)were prepared,2D[Ln_(2)(1,4-ndc)_(3)(DMF)_(4)]_(n)·nH_(2)O(Ln=Sm 1,Eu 2,Dy 3,Tb 4)and 3D[Ln_(4)(2,6-ndc)_(6)(μ_(2)H_(2)O)2(H_(2)O)_(4)]n·2nH_(2)O(Ln=Sm 5,Eu 6,Dy 7,Tb 8),where 1,4-H_(2)ndc=1,4-naphthalene dicarboxylate acid,2,6-H_(2)ndc=2,6-napthalene dicarboxylate acid,DMF=N,N-dimethylformamide.Merely compounds 2 and 6 show remarkable X-ray scintillation performance via the characteristic red emissions of Eu(Ⅲ)ions,in which the absorbed energy from the triplet states of the organic moieties can be transferred more efficiently to the resonance emission levels of Eu(Ⅲ)ions than other lanthanide(Ⅲ)ions.The X-ray dosage rate detection limits of 2 and 6 are superior to the standard for the medical X-ray diagnosis dosage rate.As proofs-of-concepts,matrix-mixed membranes fabricated with 2 and 6 have achieved remarkable X-ray imaging with high resolution for practical object shooting.展开更多
CeCO_(3)OH has a unique crystal structure and excellent optical,electronic and catalytic properties,which has been widely investigated for many applications.Interestingly,ceria obtained from CeCO_(3)OH has a morpholog...CeCO_(3)OH has a unique crystal structure and excellent optical,electronic and catalytic properties,which has been widely investigated for many applications.Interestingly,ceria obtained from CeCO_(3)OH has a morphology that is similar to that of the precursor,and the CeO_(2)-based products obtained from CeCO_(3)OH exhibit outstanding properties,such as catalytic performances,owing to their designed morphology and oxygen vacancies(OVs).To introduce CeCO_(3)OH into a wider range of potential researchers,we first systematically review the physico-chemical properties,synthesis,reaction and morphology tuning mechanism of CeCO_(3)OH,and summarize the conversion behavior from CeCO_(3)OH to ceria.Then,we thoroughly survey the applications of CeCO_(3)OH and its conversion products.Suggestions for further investigations of CeCO_(3)OH are also made in this review.It is hoped that the exhaustive co mpilation of the valuable properties and considerable potential investigations of CeCO_(3)OH will promote further applications of CeCO_(3)OH and CeO_(2)-based functional materials.展开更多
文摘Lanthanide complexes of a steroid-substituted benzocrown ether were synthesised. The metal-to-ligand ratio of all the metal complexes is 1∶1. The ligand 4′-[(cholesteryloxy)carbonyl]-benzo-15-crown-5 is a monotropic liquid crystal, displaying a cholesteric mesophase. The lanthanide complexes with nitrate counter-ions form a highly viscous mesophase, decomposing at the clearing point. The transition temperatures change as a function of the lanthanide ion. The corresponding lanthanide complexes with dodecylsulphate (DOS) counter-ions do not form a mesophase. In both cases, the metal complexes have a much lower melting point than the parent ligand.
基金supported by the National Natural Science Foundation of China(Nos.21971240 and 21827813)the National Key R&D Program of China(No.2017YFA0206802)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB20000000).
文摘X-ray detection and imaging via scintillators has been utilized in missions worldwide within areas of scientific research,medical industry,military defense and homeland security.Commercial scintillators are costly with high energy consumption through the sintering.It is of great significance to seek alternative scintillating materials for sensitive X-ray detection in the next-generation.Herein,eight structure-defined Ln(Ⅲ)-based metal-organic frameworks(Ln-MOFs)were prepared,2D[Ln_(2)(1,4-ndc)_(3)(DMF)_(4)]_(n)·nH_(2)O(Ln=Sm 1,Eu 2,Dy 3,Tb 4)and 3D[Ln_(4)(2,6-ndc)_(6)(μ_(2)H_(2)O)2(H_(2)O)_(4)]n·2nH_(2)O(Ln=Sm 5,Eu 6,Dy 7,Tb 8),where 1,4-H_(2)ndc=1,4-naphthalene dicarboxylate acid,2,6-H_(2)ndc=2,6-napthalene dicarboxylate acid,DMF=N,N-dimethylformamide.Merely compounds 2 and 6 show remarkable X-ray scintillation performance via the characteristic red emissions of Eu(Ⅲ)ions,in which the absorbed energy from the triplet states of the organic moieties can be transferred more efficiently to the resonance emission levels of Eu(Ⅲ)ions than other lanthanide(Ⅲ)ions.The X-ray dosage rate detection limits of 2 and 6 are superior to the standard for the medical X-ray diagnosis dosage rate.As proofs-of-concepts,matrix-mixed membranes fabricated with 2 and 6 have achieved remarkable X-ray imaging with high resolution for practical object shooting.
基金supported by the National Natural Science Foundation of China (52164025)Basic Research Program from Science&Technology Department of Guizhou Province (20201Y219)Natural Science Research Project of Guizhou Provincial Department of Education (2022041)。
文摘CeCO_(3)OH has a unique crystal structure and excellent optical,electronic and catalytic properties,which has been widely investigated for many applications.Interestingly,ceria obtained from CeCO_(3)OH has a morphology that is similar to that of the precursor,and the CeO_(2)-based products obtained from CeCO_(3)OH exhibit outstanding properties,such as catalytic performances,owing to their designed morphology and oxygen vacancies(OVs).To introduce CeCO_(3)OH into a wider range of potential researchers,we first systematically review the physico-chemical properties,synthesis,reaction and morphology tuning mechanism of CeCO_(3)OH,and summarize the conversion behavior from CeCO_(3)OH to ceria.Then,we thoroughly survey the applications of CeCO_(3)OH and its conversion products.Suggestions for further investigations of CeCO_(3)OH are also made in this review.It is hoped that the exhaustive co mpilation of the valuable properties and considerable potential investigations of CeCO_(3)OH will promote further applications of CeCO_(3)OH and CeO_(2)-based functional materials.