高酸度下二(2-乙基己基)亚砜萃取钯的机理研究

本文研究了DEHSO在[HCl]=8N条件下萃取Pd(Ⅱ)的机理,通过斜率法、Asmus法、饱和法确定了亚砜的配位数。并通过萃合物的元素分析、紫外光谱和红外光谱的研究推断出萃合物的组成、结构和萃取反应机理。     

Evaluation of single-ion conductances in nonaqueous solvents at 25°C by the use of tetrabutylammonium tetrabutylboride as a reference electrolyte

Precise conductances for tetrabutylammonium tetrabutylboride (Bu₄NBBu₄) at 25°C have been measured in a number of nonaqueous solvents, and the data have been analyzed by the 1957 Fuoss-Onsager conductance equation. Limiting ion conductances for the Bu₄N⁺ ion at infinite dilution ₀(Bu ₄ N ⁺) in various solvents have been evaluated by dividing ₀ values of the salt into two equal parts. The ₀(Bu ₄ N ⁺) values so obtained are in fairly good agreement (within±0.1–3.5%) with the corresponding values determined from direct transference number measurements in these solvents.     

Extraction and coordination studies of carbamoyl methyl sulfoxide (CMSO) with uranyl bis(β-diketonates). Synthesis and molecular structure of [{UO2(DBM)2}2C6H5CH2SOCH2CONHC6H5]

The carbamoyl methyl sulfoxide compounds of uranyl bis(β-diketonate) of the types [UO₂(DBM)₂CMSO] and [{UO₂(DBM)₂}₂CMSO] (where HDBM = C₆H₅COCH₂COC₆H₅; CMSO = C₆H₅CH₂SOCH₂CONHC₆H₅ or C₆H₅SOCH₂CONⁱPr₂) have been synthesized and characterized by IR and NMR spectroscopic techniques and elemental analysis. Spectral studies show that CMSO acts as a monodentate ligand in [UO₂(DBM)₂CMSO] compounds and bonds through the sulfoxo oxygen atom to the uranyl group. It acts as a bridging bidentate ligand in [{UO₂(DBM)₂}₂CMSO] compounds and bonds through both the sulfoxo and carbamoyl oxygen atoms to two different uranyl groups. The structure of the compound [{UO₂(DBM)₂}₂C₆H₅CH₂SOCH₂CONHC₆H₅] confirms the bridging bidentate mode of coordination for the CMSO ligand. Extraction studies show an enhancement in solvent extraction for the uranyl ion from nitric acid medium when a mixture of thenoyl trifluoroacetone (HTTA) and CMSO was employed.     

Enantioselective oxidation of sulfides with hydrogen peroxide catalyzed by vanadium complex of sterically hindered chiral Schiff bases

Sterically hindered chiral Schiff base ligands 4a-d were prepared from an aldehyde derived from BINOL. The vanadium complexes of the ligands catalyze an efficient, enantioselective H₂O₂-promoted sulfoxidation of alkyl aryl sulfides, and enantioselectivities as high as 98-99% ee are observed in the sulfoxidation of benzyl aryl sulfides.     

Oxidation of γ-stannyl sulfides by monochloramine CB and hydrogen peroxide

The first γ-trimethylstannyl sulfimide, Me³Sn(CH₂)₃S(=NSO₂Ar)C₅H₁₁-n, was synthesized by oxidative imination of Me₃Sn(CH₂)₃SC₅H₁₁-n with ArSO₂(Na)Cl (Ar=C₆H₄Cl-4). Oxidation of γ-trimethylstannyl sulfimide by an alkaline solution of H₂O₂ gave γ-trimethylstannyl sulfoximide, Me₃Sn(CH₂)₃S(O)(=NSO₂Ar)C₅H₁₁-n, and γ-trimethylstannyl sulfone, Me₃Sn(CH₂)₃SO₂C₅H₁₁-n, the latter compound resulting from hydrolysis of the arylsulfimide group. Oxidation of stannyl sulfide by hydrogen peroxide yielded γ-trimethylstannyl sulfoxide, Me₃Sn(CH₂)₃S(O)C₅H₁₁-n (under mild conditions) or γ-trimethylstannyl sulfone (under more severe conditions). Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 371–374, February, 1997.     

CoFe2O4@SiO2‐CPTES‐Guanidine‐Cu(II): A novel and reusable nanocatalyst for the synthesis of 2,3‐dihydroquinazolin‐4(1H)‐ones and polyhydroquinolines and oxidation of sulfides

CoFe₂O₄@SiO₂‐CPTES‐Guanidine‐Cu(II) magnetic nanoparticles were synthesized and used as a new, inexpensive and efficient heterogeneous catalyst for the synthesis of polyhydroquinolines and 2,3‐dihydroquinazoline‐4(1H)‐ones and for the oxidation of sulfides. The structure of this nanocatalyst was characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, vibrating sample magnetometry, thermogravimetric analysis, X‐ray diffraction and inductively coupled plasma optical emission spectrometry. Simple preparation, high catalytic activity, simple operation, high yields, use of green solvents, easy magnetic separation and reusability of the catalyst are some of the advantages of this protocol.     

Studies on reactions of some ruthenium sulfoxide bipyridyl complexes with 1,4-bis(salicylidene)phenylenediamine ligand used as spacer

A dinucleating spacer 1,4-bis(salicylidene)phenylenediamine (SALPHEN) derived from 1,4-phenylenediamine and salicylaldehyde has been synthesized and characterized. The ruthenium(II) sulfoxide derivative of 2,2′-bipyridine or 1,10-phenanthroline on reaction with this ligand resulted in the formation of eight dinuclear complexes, which were characterized by elemental analyses, conductivity measurements, magnetic susceptibility, FT-IR, fast atom bombardment-mass spectra, electronic spectroscopy, ¹H-NMR, ¹³C{¹H}-NMR, and ²D-NMR spectra (HETCOR). The prepared complexes have two different formulations, [{trans-RuCl₂(so)(N–N′)}₂(μ-SALPHEN)] and [{cis-RuCl₂(so)(N–N′)}₂(μ-SALPHEN)], where so?=?dimethyl sulfoxide (DMSO)/tetramethylene sulfoxide (TMSO), N–N′?=?2,2′-bipyridine/1,10-phenanthroline, and SALPHEN?=?1,4-bis(salicylidene)phenylenediamine. Two moles of ruthenium sulfoxide bipyridine precursor were coordinated to the bidentate SALPHEN through nitrogen. All the complexes possess antibacterial activity against Escherichia coli in comparison to Chloramphenicol.     

The Synthesis and Biological Activities of [5-(4-Substituted Phenylsulfinyl/Sulfonyl)-1,3-Dimethyl-1H-Pyrazol-4-Yl]-Arylmethanones

Abstract

A novel series of pyrazole derivatives containing substituted phenylsulfinyl/sulfonyl group have been synthesized via the oxidation of intermediate pyrazole sulfoether with H₂O₂ in acetic acid. The novel compounds were characterized by melting point, ¹H NMR, FT-IR, MS, and elemental analysis or HRMS. The biological activity results showed that most of the title compounds exhibit significant fungicidal activities against Alternaria solani Sorauer, Phytophthora capsici, and Corynespora cassiicola.

[Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental files: Additional text and figures.]     

Asymmetric Syntheses Based on Hexahydro-4,4,7-Trimethyl-1,3-Benzoxathians

Abstract

Earlier work concerned with a highly stereoselective asymmetric synthesis based on a 1,3-oxathiane as the ciral auxiliary reagent is reviewed and recent applications to the synthesis of the four stereoisomers of malyngolide, of (R)-(+)-γ-caprolactone (a pheromone of the Trogoderma glabrum beetle) and of (S)-(+)-mevalolactone are presented. The mechanism underlying this asymmetric synthesis is discussed briefly.