523-21-7 Usage
Chemical Properties
dark green powder
Uses
Different sources of media describe the Uses of 523-21-7 differently. You can refer to the following data:
1. As a reagent for barium and strontium.
2. Sodium rhodizonate dibasic can be employed as a reactant in the synthesis of: Dihydroxyquinone carbonate by cyclocondensation reaction with phosgene. Zwitterionic systems by condensation of heteroaryl-boronic acids.
Purification Methods
The free acid is obtained by acidifiying and extracting with Et2O, drying (MgSO4), filtering, evaporating and distilling in a vacuum (b 155-160o/14mm). The free acid solidifies on cooling, and the colourless crystals can be recrystallised from tetrahydrofuran/pet ether or *C6H6. It forms a dihydrate m 130-140o. The pure di Na salt is formed by dissolving the acid in 2 equivalents of NaOH and evaporating in a vacuum. It forms violet crystals which give an orange solution in H2O that is unstable for extended periods even at 0o, and should be prepared freshly before use. Salts of rhodizonic acid cannot be purified by recrystallisation without great loss due to conversion to crotonate, so that the original material must be prepared anew if pure salt is required. It can be washed with NaOAc solution, then EtOH, to remove excess NaOAc, dried under vacuum and stored in the dark. [UV and tautomerism: Schwarzenbach & Suter Helv Chim Acta 24 617 1941, Polarography: Preisler & Berger J Am Chem Soc 64 67 1942, Souchay & Taibouet J Chim Phys 49 C108 1952, Beilstein 8 H 535, 8 II 572, 8 III 4214, 8 IV 3609.]
Check Digit Verification of cas no
The CAS Registry Mumber 523-21-7 includes 6 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 3 digits, 5,2 and 3 respectively; the second part has 2 digits, 2 and 1 respectively.
Calculate Digit Verification of CAS Registry Number 523-21:
(5*5)+(4*2)+(3*3)+(2*2)+(1*1)=47
47 % 10 = 7
So 523-21-7 is a valid CAS Registry Number.
InChI:InChI=1/C6H2O6.2Na/c7-1-2(8)4(10)6(12)5(11)3(1)9;;/h7-8H;;/q;2*+1
523-21-7Relevant articles and documents
Oxocarbon Salts for Fast Rechargeable Batteries
Zhao, Qing,Wang, Jianbin,Lu, Yong,Li, Yixin,Liang, Guangxin,Chen, Jun
supporting information, p. 12528 - 12532 (2016/10/13)
Oxocarbon salts (M2(CO)n) prepared through one-pot proton exchange reactions with different metal ions (M=Li, Na, K) and frameworks (n=4, 5, 6) have been rationally designed and used as electrodes in rechargeable Li, Na, and K-ion batteries. The results show that M2(CO)5/M2(CO)6salts can insert two or four metal ions reversibly, while M2(CO)4shows less electrochemical activity. Especially, we discover that the K2C6O6electrode enables ultrafast potassium-ion insertion/extraction with 212 mA h g?1at 0.2 C and 164 mA h g?1at 10 C. This behavior can be ascribed to the natural semiconductor property of K2C6O6with a narrow band gap close to 0.9 eV, the high ionic conductivity of the K-ion electrolyte, and the facilitated K-ion diffusion process. Moreover, a first example of a K-ion battery with a rocking-chair reaction mechanism of K2C6O6as cathode and K4C6O6as anode is introduced, displaying an operation voltage of 1.1 V and an energy density of 35 Wh kg?1. This work provides an interesting strategy for constructing rapid K-ion batteries with renewable and abundant potassium materials.
