1198-55-6Relevant articles and documents
Bis(dioxolene)(bipyridine)ruthenium Redox Series
Lever, A. B. P.,Auburn, Pamela R.,Dodsworth, Elaine S.,Haga, Masa-aki,Liu, Wei,et al.
, p. 8076 - 8084 (1988)
Complexes of the general formula n+ have been prepared where (bpy) is 2,2'-bipyridine and n = -1, 0, +1.The dioxolene ligand is 1,2-dihydroxybenzene (cathechol), 3,5-di-tert-butyl- or 3,4,5,6-tetrachloro-1,2-dihydroxybenzene which may formally exist in the catecholate, semiquinone, or quinone oxidation state.Redox series of up to five members have been prepared by controlled potential electrolysis of the parent species or, in some cases, by chemical oxidation or reduction.Electrochemistry, magnetism, X-ray structural data and ultraviolet, visible and near infrared electronic, resonance Raman, vibrational (FTIR), nuclear magnetic resonance, electron spin resonance and photoelectron spectra, for various members of the redox series, are discussed in terms of theelectronic structures (effective oxidation states, delocalization) of the complexes.Apparent conflicts between results obtained with different techniques are resolved by using a simple, quantitative MO model.
May,Kaiser
, p. 592,594 (1972)
Bis(perchlorocatecholato)silane—A Neutral Silicon Lewis Super Acid
Maskey, Rezisha,Sch?dler, Marcel,Legler, Claudia,Greb, Lutz
, p. 1717 - 1720 (2018)
No neutral silicon Lewis super acids are known to date. We report on the synthesis of bis(perchlorocatecholato)silane and verify its Lewis super acidity by computation (DLPNO-CCSD(T)) and experiment (fluoride abstraction from SbF6?). The exceptional affinity towards donors is further demonstrated by, for example, the characterization of an unprecedented SiO4F2 dianion and applied in the first hydrodefluorination reaction catalyzed by a neutral silicon Lewis acid. Given the strength and convenient access to this new Lewis acid, versatile applications might be foreseen.
Metal-free reduction of unsaturated carbonyls, quinones, and pyridinium salts with tetrahydroxydiboron/water
Li, Tiejun,Peng, Henian,Tang, Wenjun,Tian, Duanshuai,Xu, Guangqing,Yang, He
, p. 4327 - 4337 (2021/05/31)
A series of unsaturated carbonyls, quinones, and pyridinium salts have been effectively reduced to the corresponding saturated carbonyls, dihydroxybenzenes, and hydropyridines in moderate to high yields with tetrahydroxydiboron/water as a mild, convenient, and metal-free reduction system. Deuterium-labeling experiments have revealed this protocol to be an exclusive transfer hydrogenation process from water. This journal is
Effect of oxalate and pH on photodegradation of pentachlorophenol in heterogeneous irradiated maghemite System
Lan, Qing,Cao, Meiyuan,Ye, Zhijun,Zhu, Jishu,Chen, Manjia,Chen, Xuequan,Liu, Chengshuai
, p. 198 - 206 (2016/07/06)
Photochemical degradation in the system of iron oxides and oxalic acid (OX) is the important reaction for detoxification of organic pollutants in natural environments, including surface soils, surface water, and even aerosols, and it was more effective at low pH according to previous studies. However, in this study, the photodegradation of pentachlorophenol (PCP) proceeded rapidly at different pH conditions in the system with maghemite and OX under UV light illumination. It was observed that the removal of PCP was 77.7% ± 0.90%, 79.9% ± 0.80% and 74.3% ± 1.50% at initial pH of 3.5, 5.0 and 7.0, respectively. To explore the degradation mechanism, the interaction of OX and maghemite were systematically studied as a function of pH. The presence of OX of 1.2 mM effectively decreased the iso-electric point (iep) of the maghemite from 5.6 to 1.8. The maximum adsorption amount of maghemite adsorbing OX increased with increasing pH value from 208 mmol kg-1 at pH = 3.5 to 293 mmol kg-1 at pH = 9.0. However, PCP (0.0375 mM) inhibited the adsorption of oxalic acid at pH = 3.5 and pH = 5.0 but promoted it at pH = 7.0 and pH = 9.0. When the initial content of OX was 1.2 mM, the highly active compounds of Fe(C2O4)33- as Fe(III) and Fe(C2O4)22- as Fe(II) were the dominant species at different pH. The formation of H2O2 also relied on the value of pH and the concentration range of H2O2 during PCP degradation was 0-1.67 mg L-1, 0-1.16 mg L-1 and 0-0.16 mg L-1at initial pH of 3.5, 5.0 and 7.0, respectively. The low pH conditions favored the iron cycling, the H2O2 generation and the broken of aromatic ring of PCP, so as to enhance the degradation rates of PCP. At the high pH conditions, due to the slowdown of the iron cycling and the decreased amount of H2O2 formation, the direct photolysis was responsible for the enhanced degradation of PCP. The foundation of high photochemical efficiencies of OX and maghemite for PCP degradation at large-scale pH conditions improves the photochemical mechanisms of OX-iron oxide system and is of important for understanding the transformation of organic pollutants in light environments.
