An exploratory multinuclear magnetic resonance(MR)and magnetic resonance imaging(MRI)study was performed on lithium-ion battery cells with ^(7)Li,^(19)F,and ^(1)H measurements.A variable field superconducting magnet w...An exploratory multinuclear magnetic resonance(MR)and magnetic resonance imaging(MRI)study was performed on lithium-ion battery cells with ^(7)Li,^(19)F,and ^(1)H measurements.A variable field superconducting magnet with a fixed frequency parallel-plate radiofrequency(RF)probe was employed in the study.The magnetic field was changed to set the resonance frequency of each nucleus to the fixed RF probe frequency of 33.7 MHz.Two cartridge-like lithium-ion cells,with graphite anodes and LiNi_(0.5)Mn_(0.3)Co_(0.2)O_(2)(NMC)cathodes,were interrogated.One cell was pristine,and one was charged to a cell voltage of 4.2 V.The results presented demonstrate the great potential of the variable field magnet approach in multinuclear measurement of lithium-ion batteries.These methods open the door for developing faster and simpler methods for detecting,quantifying,and interpreting MR and MRI data from lithium-ion and other batteries.展开更多
Embedding metal clusters in surface-supported metal-organic frameworks gives rise to multinuclear metal-organic coordination structures(MMOCs).The controllable configurations,exposed clusters,and multilevel interactio...Embedding metal clusters in surface-supported metal-organic frameworks gives rise to multinuclear metal-organic coordination structures(MMOCs).The controllable configurations,exposed clusters,and multilevel interactions of MMOCs imply numerous potential applications,such as in catalysis,light-energy conversion,spintronics,and molecular electronics.Thus,the fabrication of MMOCs has been investigated extensively.According to the formation mechanism of metal clusters,we summarize five types of MMOCs.Attractive properties,e.g.,magnetism,charge transfer and chirality,emerge in these systems.The surface-supported feature enables researchers to detect these properties via surface-sensitive techniques,such as scanning tunneling microscopy/spectroscopy,X-ray photoelectron spectroscopy,noncontact atomic force microscopy and local contact potential difference measurement.In addition,the results obtained from density functional theory calculations can be mutually verified with experiments.These studies pave the way for further applications of MMOCs.展开更多
The complexation oflanthanide(Ⅲ) cations with 1,2-propanediaminetetraacetate (1,2-PDTA) in aqueous solution has been investigated by ^(23)Na,^(35)Cl,~2H and ^(17)O NMR shift measurements.It has been shown that the co...The complexation oflanthanide(Ⅲ) cations with 1,2-propanediaminetetraacetate (1,2-PDTA) in aqueous solution has been investigated by ^(23)Na,^(35)Cl,~2H and ^(17)O NMR shift measurements.It has been shown that the contact shifts are dominant for ^(17)O,^(35)Cl and ~2H (only for the heavier lanthanide series) and the pseudocontact shifts are dominant for ^(23)Na.It is suggested that the 1,2-PDTA ligand is bound pentadentately via the two nitrogens and the three carboxylates for the lighter lanthanide complexes,hexdentately via the two nitrogens and the four carboxylates for the heavier ones.The numbers of the water coordinated were determined.The small amount of chloride anion in inner coordination sphere was observed.展开更多
Binary mixtures of alcohols(ethyl,n-butyl and n-amyl)with several aprotic sol- vents,such as acetone,dioxane,THF,DMSO and DMF have been studied systematically by ~1H,^(13)C,^(15)N and ^(17)O NMR measurements.The conce...Binary mixtures of alcohols(ethyl,n-butyl and n-amyl)with several aprotic sol- vents,such as acetone,dioxane,THF,DMSO and DMF have been studied systematically by ~1H,^(13)C,^(15)N and ^(17)O NMR measurements.The concentration dependence of chemical shift of the solvent was used to evaluate equilibrium constants of the complexation of alcohols with the solvents.A relationship between the proton shift of alcohol uncombined with the solvent and its concentration was found,and the fraction of unassociated hydroxyl groups was thus quantitatively described.The effect of solvent on self association and complexation of the alcohol is discussed on the basis of the electron donicity of the solvents.展开更多
Concise chemistry leads to a family of heptanuclear Co^(Ⅱ)-clusters,[Co_(7)(N_(3))_(12)(CH_(3)CN)_(12)][Y_(2)(NO_(3))_(4)(piv)_(4)]·2CH_(3)CN(DC1)(pivH=pivalic acid),[Co_(7)(N_(3))_(12)(CH_(3)CN)_(10)(NO_(3))_(0...Concise chemistry leads to a family of heptanuclear Co^(Ⅱ)-clusters,[Co_(7)(N_(3))_(12)(CH_(3)CN)_(12)][Y_(2)(NO_(3))_(4)(piv)_(4)]·2CH_(3)CN(DC1)(pivH=pivalic acid),[Co_(7)(N_(3))_(12)(CH_(3)CN)_(10)(NO_(3))_(0.4)(Cl)_(1.6)]·4CH_(3)CN(DC2)and[Co_(7)(N_(3))_(12)(CH_(3)CN)_(10)(NO_(3))_(2)]·4CH_(3)CN(DC3),in which the metal ions are exclusively bridged by end-on azido ligands to stabilize a beautiful disk-like topology.The resulting clusters exhibit interesting structural transformations and thermodynamically-distinct steady states verified by theoretical calcula-tions.Magnetic studies reveal the first observation of zero-field SMM behaviour in disk-like heptanuclear Co^(Ⅱ)complexes.展开更多
The smoke sample from the Angang Iron Steel Companys coke oven has been analysed by GC/MS. Thirty two multinuclear aromatic hydrocarbon compounds have been detected and twenty of them are world accepted as focal poi...The smoke sample from the Angang Iron Steel Companys coke oven has been analysed by GC/MS. Thirty two multinuclear aromatic hydrocarbon compounds have been detected and twenty of them are world accepted as focal poisonous.展开更多
基金BJB thanks the Canada Chairs program for a Research Chair in MRI of Materials[950e230894]an NSERC Discovery Grant[2015-6122]GRG thanks NSERC for a Discovery Grant[RGPIN-2017-06095].
文摘An exploratory multinuclear magnetic resonance(MR)and magnetic resonance imaging(MRI)study was performed on lithium-ion battery cells with ^(7)Li,^(19)F,and ^(1)H measurements.A variable field superconducting magnet with a fixed frequency parallel-plate radiofrequency(RF)probe was employed in the study.The magnetic field was changed to set the resonance frequency of each nucleus to the fixed RF probe frequency of 33.7 MHz.Two cartridge-like lithium-ion cells,with graphite anodes and LiNi_(0.5)Mn_(0.3)Co_(0.2)O_(2)(NMC)cathodes,were interrogated.One cell was pristine,and one was charged to a cell voltage of 4.2 V.The results presented demonstrate the great potential of the variable field magnet approach in multinuclear measurement of lithium-ion batteries.These methods open the door for developing faster and simpler methods for detecting,quantifying,and interpreting MR and MRI data from lithium-ion and other batteries.
基金supported by the Ministry of Science and Technology(2018YFA0306003)National Natural Science Foundation of China(22225202,22132007,21991132,21972002,22172002,21972067).
文摘Embedding metal clusters in surface-supported metal-organic frameworks gives rise to multinuclear metal-organic coordination structures(MMOCs).The controllable configurations,exposed clusters,and multilevel interactions of MMOCs imply numerous potential applications,such as in catalysis,light-energy conversion,spintronics,and molecular electronics.Thus,the fabrication of MMOCs has been investigated extensively.According to the formation mechanism of metal clusters,we summarize five types of MMOCs.Attractive properties,e.g.,magnetism,charge transfer and chirality,emerge in these systems.The surface-supported feature enables researchers to detect these properties via surface-sensitive techniques,such as scanning tunneling microscopy/spectroscopy,X-ray photoelectron spectroscopy,noncontact atomic force microscopy and local contact potential difference measurement.In addition,the results obtained from density functional theory calculations can be mutually verified with experiments.These studies pave the way for further applications of MMOCs.
基金Project supported by the National Natural Science Foundation of China
文摘The complexation oflanthanide(Ⅲ) cations with 1,2-propanediaminetetraacetate (1,2-PDTA) in aqueous solution has been investigated by ^(23)Na,^(35)Cl,~2H and ^(17)O NMR shift measurements.It has been shown that the contact shifts are dominant for ^(17)O,^(35)Cl and ~2H (only for the heavier lanthanide series) and the pseudocontact shifts are dominant for ^(23)Na.It is suggested that the 1,2-PDTA ligand is bound pentadentately via the two nitrogens and the three carboxylates for the lighter lanthanide complexes,hexdentately via the two nitrogens and the four carboxylates for the heavier ones.The numbers of the water coordinated were determined.The small amount of chloride anion in inner coordination sphere was observed.
文摘Binary mixtures of alcohols(ethyl,n-butyl and n-amyl)with several aprotic sol- vents,such as acetone,dioxane,THF,DMSO and DMF have been studied systematically by ~1H,^(13)C,^(15)N and ^(17)O NMR measurements.The concentration dependence of chemical shift of the solvent was used to evaluate equilibrium constants of the complexation of alcohols with the solvents.A relationship between the proton shift of alcohol uncombined with the solvent and its concentration was found,and the fraction of unassociated hydroxyl groups was thus quantitatively described.The effect of solvent on self association and complexation of the alcohol is discussed on the basis of the electron donicity of the solvents.
基金supported by the National Natural Science Foundation of China(NSFC,Nos.21863009,22063008)the Natural Science Foundation of Ningxia Province(Nos.2023AAC03014,2023AAC03227,2021AAC03136,2021BEB04062)+1 种基金the Young Top-notch Talent Cultivation Program of Ningxia Province,the Discipline Project of Ningxia(No.NXYLXK2017A04)the China Postdoctoral Science Foundation(No.2022M723148).
文摘Concise chemistry leads to a family of heptanuclear Co^(Ⅱ)-clusters,[Co_(7)(N_(3))_(12)(CH_(3)CN)_(12)][Y_(2)(NO_(3))_(4)(piv)_(4)]·2CH_(3)CN(DC1)(pivH=pivalic acid),[Co_(7)(N_(3))_(12)(CH_(3)CN)_(10)(NO_(3))_(0.4)(Cl)_(1.6)]·4CH_(3)CN(DC2)and[Co_(7)(N_(3))_(12)(CH_(3)CN)_(10)(NO_(3))_(2)]·4CH_(3)CN(DC3),in which the metal ions are exclusively bridged by end-on azido ligands to stabilize a beautiful disk-like topology.The resulting clusters exhibit interesting structural transformations and thermodynamically-distinct steady states verified by theoretical calcula-tions.Magnetic studies reveal the first observation of zero-field SMM behaviour in disk-like heptanuclear Co^(Ⅱ)complexes.
文摘The smoke sample from the Angang Iron Steel Companys coke oven has been analysed by GC/MS. Thirty two multinuclear aromatic hydrocarbon compounds have been detected and twenty of them are world accepted as focal poisonous.
