A new series of metal complex carboxylates（MCC）made of [Co（en）3]3＋（MC）and either 2,6-naphthalenedicarboxylic（NDC）or 4,4-biphenyldicarboxylic（BPDC）were synthesized and structurally characterized.The four new...A new series of metal complex carboxylates（MCC）made of [Co（en）3]3＋（MC）and either 2,6-naphthalenedicarboxylic（NDC）or 4,4-biphenyldicarboxylic（BPDC）were synthesized and structurally characterized.The four new compounds have a general formula（MC）2（C）3·n（guest）with the guests of dimethylformamide（DMF）and dimethyl sulfoxide（DMSO）and water.All the structures represent a pillared-layer type,where the layer consists of MC cations,carboxylate anions or water molecules via a large number of hydrogen bonds.The layers are pillared by the organic residues of NDC or BPDC,resulting in the inclusion cavities where the guest molecules reside.Although their topological structures are similar,they crystallize in different crystal structures due to the rearrangement of pillars and hydrogen-bonded layers.展开更多
Using the deep eutectic solvent formed of oxalic acid and choline chloride, a new charge-assisted hydrogen-bonded host framework [Co（en）312[Zr2（C2O4）7]·2H2O （1） has been obtained. The title complex crystall...Using the deep eutectic solvent formed of oxalic acid and choline chloride, a new charge-assisted hydrogen-bonded host framework [Co（en）312[Zr2（C2O4）7]·2H2O （1） has been obtained. The title complex crystallizes in the monoclinic, space group P21/n （No. 14） with a = 7.7448（10）, b = 14.5683（19）, c = 19.375（3） A, fl = 92.124（2）°, V= 2184.5（5） A3, Z = 4, Dc = 1.996 gcm-3, F（000） = 1332, μ = 1.328 mm＂1, R = 0.0353 and wR = 0.0718 （1 〉 2α（I））. Single-crystal structure analysis reveals that the title complex possesses a 3D network assembled through a multitude of charge-assisted hydrogen bonds between the in situ generated anionic coordination complexes [Zr2（C204）7]6- and metal complexes Co（en）33＋.展开更多
Sodium-ion batteries are promising for large-scale energy storage due to sodium's low cost and infinite abundance. The most popular cathodes for sodium-ion batteries, i.e., the layered sodium-containing oxides, us...Sodium-ion batteries are promising for large-scale energy storage due to sodium's low cost and infinite abundance. The most popular cathodes for sodium-ion batteries, i.e., the layered sodium-containing oxides, usually exhibit reversible host rearrangement between P-type and O-type stacking upon charge/discharge. Herein we demonstrate that such host rearrangement is unfavorable and can be suppressed by introducing transition-metal ions into sodium layers. The electrode with stabilized P3-type stacking delivers superior rate capability, high energy efficiency, and excellent cycling performance. Owing to the cation-mixing nature, it performs the lowest lattice strain among all reported cathodes for sodium-ion batteries. Our findings highlight the significance of a stable host for sodium-ion storage and moreover underline the fundamental distinction in material design strategy between lithium-and sodium-ion batteries.展开更多
基金Supported by the National Science Foundation (DMR-0600320)
文摘A new series of metal complex carboxylates（MCC）made of [Co（en）3]3＋（MC）and either 2,6-naphthalenedicarboxylic（NDC）or 4,4-biphenyldicarboxylic（BPDC）were synthesized and structurally characterized.The four new compounds have a general formula（MC）2（C）3·n（guest）with the guests of dimethylformamide（DMF）and dimethyl sulfoxide（DMSO）and water.All the structures represent a pillared-layer type,where the layer consists of MC cations,carboxylate anions or water molecules via a large number of hydrogen bonds.The layers are pillared by the organic residues of NDC or BPDC,resulting in the inclusion cavities where the guest molecules reside.Although their topological structures are similar,they crystallize in different crystal structures due to the rearrangement of pillars and hydrogen-bonded layers.
基金supported by the National Natural Science Foundation of China(Nos.21301024,21103017)the Fundamental Research Funds for the Central Universities(N120305003)
文摘Using the deep eutectic solvent formed of oxalic acid and choline chloride, a new charge-assisted hydrogen-bonded host framework [Co（en）312[Zr2（C2O4）7]·2H2O （1） has been obtained. The title complex crystallizes in the monoclinic, space group P21/n （No. 14） with a = 7.7448（10）, b = 14.5683（19）, c = 19.375（3） A, fl = 92.124（2）°, V= 2184.5（5） A3, Z = 4, Dc = 1.996 gcm-3, F（000） = 1332, μ = 1.328 mm＂1, R = 0.0353 and wR = 0.0718 （1 〉 2α（I））. Single-crystal structure analysis reveals that the title complex possesses a 3D network assembled through a multitude of charge-assisted hydrogen bonds between the in situ generated anionic coordination complexes [Zr2（C204）7]6- and metal complexes Co（en）33＋.
基金The financial support from the National Basic Research Program of China(2014CB932300)Natural Science Foundation of Jiangsu Province of China(BK20170630)+1 种基金NSF of China(21633003 and 51602144)sponsored by the JST-CREST ‘‘Phase Interface Science for Highly Efficient Energy Utilization",JST(Japan)
文摘Sodium-ion batteries are promising for large-scale energy storage due to sodium's low cost and infinite abundance. The most popular cathodes for sodium-ion batteries, i.e., the layered sodium-containing oxides, usually exhibit reversible host rearrangement between P-type and O-type stacking upon charge/discharge. Herein we demonstrate that such host rearrangement is unfavorable and can be suppressed by introducing transition-metal ions into sodium layers. The electrode with stabilized P3-type stacking delivers superior rate capability, high energy efficiency, and excellent cycling performance. Owing to the cation-mixing nature, it performs the lowest lattice strain among all reported cathodes for sodium-ion batteries. Our findings highlight the significance of a stable host for sodium-ion storage and moreover underline the fundamental distinction in material design strategy between lithium-and sodium-ion batteries.
