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81.
《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(1):101-111
Treatment of titanyl sulfate in about 60 mM sulfuric acid with NaLOEt (LOEt?=[(η5‐C5H5)Co{P(O)(OEt)2}3]?) afforded the μ‐sulfato complex [(LOEtTi)2(μ‐O)2(μ‐SO4)] ( 2 ). In more concentrated sulfuric acid (>1 M ), the same reaction yielded the di‐μ‐sulfato complex [(LOEtTi)2(μ‐O)(μ‐SO4)2] ( 3 ). Reaction of 2 with HOTf (OTf=triflate, CF3SO3) gave the tris(triflato) complex [LOEtTi(OTf)3] ( 4 ), whereas treatment of 2 with Ag(OTf) in CH2Cl2 afforded the sulfato‐capped trinuclear complex [{(LOEt)3Ti3(μ‐O)3}(μ3‐SO4){Ag(OTf)}][OTf] ( 5 ), in which the Ag(OTf) moiety binds to a μ‐oxo group in the Ti3(μ‐O)3 core. Reaction of 2 in H2O with Ba(NO3)2 afforded the tetranuclear complex (LOEt)4Ti4(μ‐O)6 ( 6 ). Treatment of 2 with [{Rh(cod)Cl}2] (cod=1,5‐cyclooctadiene), [Re(CO)5Cl], and [Ru(tBu2bpy)(PPh3)2Cl2] (tBu2bpy=4,4′‐di‐tert‐butyl‐2,2′‐dipyridyl) in the presence of Ag(OTf) afforded the heterometallic complexes [(LOEt)2Ti2(O)2(SO4){Rh(cod)}2][OTf]2 ( 7 ), [(LOEt)2Ti(O)2(SO4){Re(CO)3}][OTf] ( 8 ), and [{(LOEt)2Ti2(μ‐O)}(μ3‐SO4)(μ‐O)2{Ru(PPh3)(tBu2bpy)}][OTf]2 ( 9 ), respectively. Complex 9 is paramagnetic with a measured magnetic moment of about 2.4 μB. Treatment of zirconyl nitrate with NaLOEt in 3.5 M sulfuric acid afforded [(LOEt)2Zr(NO3)][LOEtZr(SO4)(NO3)] ( 10 ). Reaction of ZrCl4 in 1.8 M sulfuric acid with NaLOEt in the presence Na2SO4 gave the μ‐sulfato‐bridged complex [LOEtZr(SO4)(H2O)]2(μ‐SO4) ( 11 ). Treatment of 11 with triflic acid afforded [(LOEt)2Zr][OTf]2 ( 12 ), whereas reaction of 11 with Ag(OTf) afforded a mixture of 12 and trinuclear [{LOEtZr(SO4)(H2O)}3(μ3‐SO4)][OTf] ( 13 ). The ZrIV triflato complex [LOEtZr(OTf)3] ( 14 ) was prepared by reaction of LOEtZrF3 with Me3SiOTf. Complexes 4 and 14 can catalyze the Diels–Alder reaction of 1,3‐cyclohexadiene with acrolein in good selectivity. Complexes 2 – 5 , 9 – 11 , and 13 have been characterized by X‐ray crystallography. 相似文献
82.
83.
A convenient method for the synthesis of quinoxalines catalysed by metal hydrogen sulfates by the reaction of 1,2‐diamino compounds and 1,2‐dicarbonyl compounds in ethanol as solvent at room temperature is reported. 相似文献
84.
A calorimetric study of the kinetics and thermodynamics of the attack of a phosphate ore from Gafsa region (Tunisia) by phosphoric acid and by a mixture of phosphoric acid and sulfuric acids is undertaken at different temperatures. Two samples of the same ore having different grain size have been used. At 25 °C, the dissolution enthalpy in phosphoric acid solution equals −233.6 ± 2.2 J/g for both of the samples. Attack by the mixture of acids is strongly dependent on the solid granulometry. Interpretation of the calorimetric results by Avrami model shows the existence of three domains attributed to phosphate ore dissolution/H2PO4− neutralisation, hemihydrate (HH) precipitation and hemihydrate/dihydrate (DH) transformation. The attack by the acid mixture was performed at higher temperatures and showed in addition the transitional formation of the anhydrous sulfate (AH) at T ≥ 55 °C, which transforms into dihydrate after the HH/DH transformation. 相似文献
85.
Hao Wu Sabine Reimann Sophiya Siddiqui Rainer Haag Britta Siegmund Jens Dernedde Rainer Glauben 《Macromolecular bioscience》2019,19(12)
The synthetic compound dendritic polyglycerol sulfate (dPGS) is a pleiotropic acting molecule but shows a high binding affinity to immunological active molecules as L‐/P‐selectin or complement proteins leading to well described anti‐inflammatory properties in various mouse models. In order to make a comprehensive evaluation of the direct effect on the innate immune system, macrophage polarization is analyzed in the presence of dPGS on a phenotypic but also metabolic level. dPGS administered macrophages show a significant increase of MCP1 production paralleled by a reduction of IL‐10 secretion. Metabolic analysis reveals that dPGS could potently enhance the glycolysis and mitochondrial respiration in M0 macrophages as well as decrease the mitochondrial respiration of M2 macrophages. In summary the data indicate that dPGS polarizes macrophages into a pro‐inflammatory phenotype in a metabolic pathway‐dependent manner. 相似文献
86.
Yi-Lin Li Meng-Ya Ji Dr. Chun-Li Hu Dr. Jin Chen Dr. Bing-Xuan Li Dr. Yuan Lin Prof. Jiang-Gao Mao 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(19):e202200001
Through systematic experiments, two novel mercury iodate sulfates, namely, Hg2(IO3)2(SO4)(H2O) and Hg2(IO3)2(SO4) were obtained. They crystallize in monoclinic space group C2 and C2/c, respectively. Hg2(IO3)2(SO4)(H2O) exhibits the [Hg(IO3)]+ polar cationic layer inherited from Hg(IO3)2 and the three-dimensional (3D) framework inherited from HgSO4. This enables Hg2(IO3)2(SO4)(H2O) to generate a strong second harmonic generation (SHG) response of 6 times that of KH2PO4 (KDP). The structure of Hg2(IO3)2(SO4) is very similar to that of Hg2(IO3)2(SO4)(H2O), and they can be transformed into each other. Hg2(IO3)2(SO4)(H2O) shows a large optical band gap of 3.98 eV and a high dehydration temperature of 250 °C. This study indicates that by reasonable design, the introduction of multiple functional groups into a compound may combine their advantages to achieve good overall optical performance. 相似文献
87.
<正>For the first time,metal hydrogen sulfates and phosphates/silica gel have been studied as efficient and powerful solid acid catalysts in the ring opening of epoxides with thiocyanate anion.The most significant result was obtained by Al(HSO_4)_3/SiO_2 which afforded the corresponding β-hydroxy thiocyanates under mild reaction conditions and in very short reaction times.The cheapness, availability of the catalyst,ease of procedure and work-up make this method attractive for the organic synthesis. 相似文献
88.
A direct and effective method utilizing reversed-phase liquid chromatography combined with evaporative light scattering detection was developed to determine the relative ratio of different alkyl chain lengths, to quantify the average ethylene oxide (EO) level and to identify EO distribution in the presence of sodium laureth sulfates. A C8 bonded silica gel column and an acetonitrile–water gradient mobile phase containing ammonium acetate were used as the best stationary and mobile phase, respectively. The results were confirmed by nuclear magnetic resonance spectroscopy. The detection limit was 80 μg/mL and the calibration curve, i.e., the log–log plots (peak area vs. concentration), was linear in the working range of 80–4200 μg/mL with R2 values of above 0.999 (in the case of 3 mol sodium laureth sulfates). Furthermore, the application of the chromatographic method to a commercial product without pretreatment was presented. The raw material was identified by fast atom bombardment mass spectrometry. 相似文献
89.
90.
Mustafa Eskici Abdullah Karanfil M. Sabih Özer Yalçın Kabak İnci Durucasu 《合成通讯》2013,43(18):2382-2390
A practical and efficient asymmetric synthesis of (S)-dihydrokavain from known ethyl (S)-2-hydroxy-4-phenylbutanoate which is, in turn, readily available from l-malic acid as a cheap chiral pool material is described using regioselective ring-opening of the 1,2-cyclic sulfate with lithium-3,3,3-triethoxypropiolate and subsequent HgO/H2SO4-mediated lactonization as the key steps. Its opposite enantiomer (R)-dihydrokavain was also synthesized from d-malic acid using the same sequences of reactions for the purpose of optical purity determination. 相似文献