613-03-6Relevant articles and documents
Spectrophotometric determination of cobalt(II) and cyanocobalamin with vanillilfluorone and its applications
Hoshino, Mitsuru,Matsushita, Momoka,Samma, Megumi,Asano, Mamiko,Yamaguchi, Takako,Fujita, Yoshikazu
, p. 721 - 724 (2011)
Spectrophotometric determination of cobalt(II) was accomplished with vanillilfluorone (VF) in the presence of dimethylbenzyltetradecylammonium chloride (Zephiramine, Zep). In the determination of cobalt(II), Beer's law was obeyed in the range of 24-470 ng/ml, with an effective molar absorption coefficient (at 575 nm) and relative standard deviation of 1.35×105 l mol-1 cm-1 and 0.66% (n=5), respectively. The composition ratio of the colored complex was determined by the mole ratio and continuous variation methods, and it was found to be Co(II) :VF: Zep=1 : 2 : 4. Analysis of cyanocobalamin by the same procedure showed that cyanocobalamin could be determined in the concentration range of 0.5-0.11 μg/ml using the proposed method.
Direct Acetoxylation of Arenes
Hong Nguyen, Thi Anh,Hou, Duen-Ren
supporting information, p. 8127 - 8131 (2021/08/23)
Acetoxylation of arenes is an important reaction and an unmet need in chemistry. We report a metal-free, direct acetoxylation reaction using sodium nitrate under an anhydrous environment of trifluoroacetic acid, acetic acid, and acetic anhydride. Arenes (31 examples), with oxidation potentials (Eox, in V vs SCE) lower than benzene (2.48 V), were acetoxylated with good yields and regioselectivity. A stepwise, single electron-transfer mechanism is proposed.
CONCERTED PROCESSES FOR FORMING 1,2,4-TRIHYDROXYBENZENE FROM HYDROQUINONE
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Paragraph 0094, (2018/04/26)
Flow batteries incorporating an active material with one or more catecholate ligands can have a number of desirable operating features. Commercial syntheses of catechol produce significant quantities of hydroquinone as a byproduct, which presently has limited value in the battery industry and can represent a significant waste disposal issue at industrial production scales. Using a concerted, high-yield process, low-value hydroquinone can be transformed into high-value 1,2,4-trihydroxybenzene, which can be a desirable ligand for active materials of relevance in the flow battery industry. Methods for forming 1,2,4-trihydroxybenzene can include: oxidizing hydroquinone in a first reaction to form p-benzoquinone, converting the p-benzoquinone in a second reaction to form 1,2,4-triacetoxybenzene, deacetylating the 1,2,4-triacetoxybenzene in a third reaction to form 1,2,4-trihydroxybenzene, and isolating the 1,2,4-trihydroxybenzene after performing the first reaction, the second reaction and the third reaction consecutively.
9. 9 '- (3, 3' - dihydroxy - 4, 4' - b phenylate base) double-phenylfluorone reagent and its preparation method and application
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Paragraph 0020; 0023, (2017/11/16)
The invention belongs to the technical field of phenylfluorone compounds and provides a 9,9'-(3,3'-dihydroxy-4,4'-diphenylether)bifluorone reagent and a preparation method and application thereof to solve the problem that an existing phenylfluorone compound having non-ideal sensitivity and selectivity is unable to serve as a fluorescent reagent in the fluorescent detection of metal ions.Two pyranoid ring structural units are introduced in molecules, the quantity of metal ion coordination sites is increased by one time, the ability of the reagent to coordinate with metal ions is enhanced, and the fluorescent reagent good in sensitivity and selectivity is obtained.The preparation method is simple, the cost is low, properties are stable, a detection limit in nickel determination by fluorophotometric quenching process in a basic medium in the presence of a surfactant is lower that of other reagent quenching processes, cobalt determination by spectrophotometry is higher than other fluorone reagent processes in sensitivity, and a detection limit in cobalt determination by discoloring spectrophotometry is lower than that of a process using other fluorone reagents.This reagent has high detection speed for nickel and cobalt ions and is good in selectivity, high in sensitivity and high in complex stability.
