Organic 2,5-dihydroxy-1,4-benzoquinone potassium salt with ultrahigh initial coulombic efficiency for potassium-ion batteries
作者:Qijiu Deng、Congcong Tian、Zongbin Luo、Yangyang Zhou、Bo Gou、Haixuan Liu、Yingchun Ding、Rong Yang
DOI:10.1039/d0cc05248e
日期:——
A new organic 2,5-dihydroxy-1,4-benzoquinone potassium salt (K2C6H2O4) with an ultrahigh initial coulombic efficiency of 96% is proposed as an advanced anode for potassium-ion batteries.
Face-to-face stacking of dianionic quinoid rings in crystals of alkali salts of 2,5-dihydroxyquinone in view of π-system polarization
作者:Krešimir Molčanov、Biserka Kojić-Prodić、Darko Babić、Jernej Stare
DOI:10.1039/c2ce26119g
日期:——
A series of alkali (M+ = K+, NH4+, Rb+ and Cs+) salts of 2,5-dihydroxyquinone [M2+ (C6H4O4)2−] was prepared and their structures were determined by X-ray structure analysis. A less-common type of π-stacking of dianionic quinoid rings in face-to-face fashion (no offset) is observed. However, in the potassium salt of this series the stacking motif of the dianionic quinoid rings is in a herring-bone pattern
的一系列碱金属盐(M + = K +,NH 4 +,Rb +和Cs +)2,5-二羟基醌制备[M 2 +(C 6 H 4 O 4)2- ],并通过X射线结构分析确定其结构。观察到以面对面的方式(无偏移)的不常见的π型叠氮化醌环的π堆积。但是,在该系列的钾盐中,双阴离子醌型环的堆积基序呈鱼骨状,通常在芳香族化合物的堆积中观察到。根据通过DFT方法计算的相对能量,讨论了由各种阳离子诱导的不同类型的晶体结构。通过计算可以复制观察到的结构特征。醌型环的堆叠通过分散相互作用来辅助。
Tetradihydrobenzoquinonate and Tetrachloranilate Zr(IV) Complexes: Single-Crystal-to-Single-Crystal Phase Transition and Open-Framework Behavior for K<sub>4</sub>Zr(DBQ)<sub>4</sub>
The molecular complexes K-4[Zr(DBQ)](4) and K-4[Zr(CA)(4)], where DBQ(2-) and CA(2-) stand respectively for deprotonated dihydroxybenzoquinone and chloranilic acid, are reported. The anionic metal complexes consist of Zr(IV) surrounded by four O,O-chelating ligands. Besides the preparation and crystal structures for the two complexes, we show that in the solid state the DBQ complex forms a 3-D open framework (with 22% accessible volume) that undergoes a crystal-to-crystal phase transition to a compact structure upon guest molecule release. This process is reversible. In the presence of H2O, CO2, and other small molecules, the framework opens and accommodates guest molecules. CO2 adsorption isotherms show that the framework breathing occurs only when a slight gas pressure is applied. Crystal structures for both the hydrated and guest free phases of K-4[Zr(DBQ)(4)] have been investigated.
Gupta, Akhilesh K.; Gupta, Anupama; Choudhury, Anuradha, Indian Journal of Chemistry, Section A: Inorganic, Physical, Theoretical and Analytical, 2002, vol. 41, # 10, p. 2076 - 2078