In this paper,INDO perturbation theory has been extended to calculate the NMR chem- ical shifts of transition metal compounds.The nitrogen and oxygen INDO parameters have been refined by using a set of nitrogen and ox...In this paper,INDO perturbation theory has been extended to calculate the NMR chem- ical shifts of transition metal compounds.The nitrogen and oxygen INDO parameters have been refined by using a set of nitrogen and oxygen containing compounds to minimize the differences between calculated and experimental ^(13)C,^(15)N,and ^(17)O shielding constants.These refined parameters, together with optimally selected iron INDO parameters,were used to evaluate the ^(13)C chemical shifts of three iron complexes(C_5H_5)Fe(CO)_2CN,(C_5H_4CHO)_2Fe_2,and(C_5H_4CH_2OH)_2Fe.The calculated ^(13)C,^(15)N and ^(17)O shielding constants were fairly in agreement with experimental results. In addition,a good linear relationship between the calculated diamagnetic shielding constants σ~d(M)of ^(13)C,^(15)N and ^(17)O nuclei and the net charge ρ(M)of these atoms was noticed.展开更多
Recent advances in utilizing ^(17)O isotopic labeling methods for solid-state nuclear magnetic resonance(NMR)investigations of metal oxides for lithium-ion batteries have yielded extensive insights into their structur...Recent advances in utilizing ^(17)O isotopic labeling methods for solid-state nuclear magnetic resonance(NMR)investigations of metal oxides for lithium-ion batteries have yielded extensive insights into their structural and dynamic details.Herein,we commence with a brief introduction to recent research on lithium-ion battery oxide materials studied using ^(17)O solid-state NMR spectroscopy.Then we delve into a review of ^(17)O isotopic labeling methods for tagging oxygen sites in both the bulk and surfaces of metal oxides.At last,the unresolved problems and the future research directions for advancing the ^(17)O labeling technique are discussed.展开更多
文摘In this paper,INDO perturbation theory has been extended to calculate the NMR chem- ical shifts of transition metal compounds.The nitrogen and oxygen INDO parameters have been refined by using a set of nitrogen and oxygen containing compounds to minimize the differences between calculated and experimental ^(13)C,^(15)N,and ^(17)O shielding constants.These refined parameters, together with optimally selected iron INDO parameters,were used to evaluate the ^(13)C chemical shifts of three iron complexes(C_5H_5)Fe(CO)_2CN,(C_5H_4CHO)_2Fe_2,and(C_5H_4CH_2OH)_2Fe.The calculated ^(13)C,^(15)N and ^(17)O shielding constants were fairly in agreement with experimental results. In addition,a good linear relationship between the calculated diamagnetic shielding constants σ~d(M)of ^(13)C,^(15)N and ^(17)O nuclei and the net charge ρ(M)of these atoms was noticed.
基金supported by National Key R&D Program of China(2021YFA1502803)the National Natural Science Foundation of China(NSFC)(21972066,91745202)+3 种基金NSFC-Royal Society Joint Program(21661130149)L.P.thanks the Royal Society and Newton Fund for a Royal Society-Newton Advanced Fellowshipsupported by the Research Funds for the Frontiers Science Centre for Critical Earth Material Cycling,Nanjing Universitya Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Recent advances in utilizing ^(17)O isotopic labeling methods for solid-state nuclear magnetic resonance(NMR)investigations of metal oxides for lithium-ion batteries have yielded extensive insights into their structural and dynamic details.Herein,we commence with a brief introduction to recent research on lithium-ion battery oxide materials studied using ^(17)O solid-state NMR spectroscopy.Then we delve into a review of ^(17)O isotopic labeling methods for tagging oxygen sites in both the bulk and surfaces of metal oxides.At last,the unresolved problems and the future research directions for advancing the ^(17)O labeling technique are discussed.
