Acid-base properties of bis(hydrazinocarbonylmethyl) sulfoxide and its complex formation with copper(II) and nickel(II)

Behavior of physiologically active compound, bis(hydrazinocarbonylmethyl) sulfoxide, in aqueous solution has been studied by means of potentiometry, spectrophotometry, and mathematical simulation. Protolytic properties of bis(hydrazinocarbonylmethyl) sulfoxide have been described, and the formation of sodium salt has been confirmed. Composition and stability constants of bis(hydrazinocarbonylmethyl) sulfoxide complexes with copper(II) and nickel(II) have been determined, and the complexes structures have been simulated by molecular mechanics method.     

FT IR ATR Study of Molecular Interactions in the Urea/Dimethyl Sulfoxide and Urea/Diethyl Sulfoxide Binary Systems

FT IR ATR spectra of urea/dimethyl sulfoxide and urea/diethyl sulfoxide mixtures in the S=O and N—H stretching vibration regions at different molar ratios have been measured. On the basis of the band deconvolution data, various types of intermolecular associated forms, including dimers and hydrogen-bonded urea–sulfoxide complexes, have been revealed. The latter has been confirmed also by ab initio calculations.     

Vibrational spectroscopic force field studies of dimethyl sulfoxide and hexakis(dimethyl sulfoxide)scandium(III) iodide, and crystal and solution structure of the hexakis(dimethyl sulfoxide)scandium(III) ion

Hexakis(dimethyl sulfoxide)scandium(III) iodide, [Sc(OS(CH(3))(2))(6)]I(3) contains centrosymmetric hexasolvated scandium(III) ions with an Sc-O bond distance of 2.069(3) angstroms. EXAFS spectra yield a mean Sc-O bond distance of 2.09(1) angstroms for solvated scandium(III) ions in dimethyl sulfoxide solution, consistent with six-coordination. Raman and infrared absorption spectra have been recorded, also of the deuterated compound, and analysed by means of normal coordinate methods, together with spectra of dimethyl sulfoxide. The effects on the vibrational spectra of the weak intermolecular C-H...O interactions and of the dipole-dipole interactions in liquid dimethyl sulfoxide have been evaluated, in particular for the S-O stretching mode. The strong Raman band at 1043.6 cm(-1) and the intense IR absorption at 1062.6 cm(-1) have been assigned as the S-O stretching frequencies of the dominating species in liquid dimethyl sulfoxide, evaluated as centrosymmetric dimers with antiparallel polar S-O groups. The shifts of vibrational frequencies and force constants for coordinated dimethyl sulfoxide ligands in hexasolvated trivalent metal ion complexes are discussed. Hexasolvated scandium(iii) ions are found in dimethyl sulfoxide solution and in [Sc(OSMe(2))(6)]I(3). The iodide ion-dipole attraction shifts the methyl group C-H stretching frequency for (S-)C-H...I(-) more than for the intermolecular (S-)C-H...O interactions in liquid dimethyl sulfoxide.     

Combining planar and central chirality in ferrocene thiophosphine-sulfoxides

Novel chiral ferrocenylthiophosphine–sulfoxide and phosphine–sulfoxide derivatives possessing planar chirality for the ferrocene moiety and central chirality at the sulfur atom have been synthesized. These ligands can be obtained as pure diastereoisomers in both racemic and enantiomerically pure forms. Complete characterization by XRD analysis has allowed the assignment of the absolute configuration in each case. Preliminary coordination studies of the phosphine–sulfoxide ligands on platinum are also reported. These show chelating complexation by the phosphorous and sulfur atoms.     

Alkatrienyl Sulfoxides and Sulfones. Part I. 3-Methyl-1,2,4-pentatrienyl Phenyl Sulfoxide-Synthesis and Electrophile-Induced Cyclization Reactions

A method for the synthesis of the 3-methyl-1,2,4-pentatrienyl phenyl sulfoxide 3 by [2,3]-sigmatropic rearrangement of the 3-methyl-1-penten-4-yn-3-yl benzenesulfenate 2 , formed in the reaction of the 3-methyl-1-pentene-4-yn-2-ol 1 with phenylsulfenyl chloride has been created. Possibilities and restrictions of the five-membered heterocyclization in electrophile-induced reactions leading to the synthesis of the 5H-1,2-oxathiol-2-ium salts 5 , 7 , and 8 have been explored. Chlorination of the sulfoxide 2 proceeded with formation of the (E)-2-chloro-3-methylene-1,4-pentadienyl phenyl sulfoxide 4 , while the bromination afforded the 4-bromo-5H-1,2-oxathiol-2-ium bromide 5 , which after reflux in 1,2-dichloroethane eliminated hydrogen bromide and was transformed into the (E)-2-bromo-3-methylene-1,4-pentadienyl phenyl sulfoxide 6 .     

高选择性透过SO_2气体分离膜研究 Ⅱ.丙基乙烯基亚砜改性聚乙烯醇功能高分子膜的分离性能

丙基乙烯基亚砜改性聚乙醇功能高分子膜对SO_2,N_2及SO_2-N_2混合气体的渗透性能研究表明,该膜具有高选择透过SO_2的优良性能.透过SO_2的速率随着亚砜基含量的增加而增加,当亚砜基含量为25(mol)％时,经一次分离能使混合气体中SO_2的含量从1.54％提高到78.8％.     

Circular dichroism spectra and absolute configuration of some aryl methyl sulfoxides

The absorption and circular dichroism (CD) spectra of three aryl sulfoxides, i.e. (-)-(S)-1-naphthyl methyl sulfoxide, (S)-1, (-)-(S)-1-(2-methyl)naphthyl methyl sulfoxide, (S)-2 and (-)-(S)-9-phenanthryl methyl sulfoxide, (S)-3, have been interpreted by means of the coupled oscillator model formulated by DeVoe. Theoretical spectra have been calculated starting from input geometries provided by molecular mechanics (MMX) calculations and by employing standard spectroscopic parameters to describe the allowed transitions of the aromatic and the sulfoxide chromophores. The satisfactory agreement between the predicted and experimental spectra allows us to confirm the configurational assignment of these compounds as (-)/(S). The analysis of CD spectra, affording the right assignment of the absolute configuration (AC) of the alkyl aryl sulfoxides, then offers a practical alternative to the more complex vibrational circular dichroism spectroscopy and ab initio optical rotation calculation techniques that have been used very recently to assign the AC of (-)-2 and (-)-3.     

Promotion of base-catalyzed siloxane rearrangements by dimethyl sulfoxide

The effect of small amounts (0.01%–1%) of dimethyl sulfoxide on base-catalyzed polymerization and equilibration of methylsiloxanes has been examined. The addition of 0.5% of the sulfoxide increases the rate of potassium hydroxide-catalyzed polymerization of octamethylcyclotetrasiloxane by factors of 100–1000 and amounts as low as 0.01% have a large effect when low (12 ppm) catalyst concentrations are used. The rate of basecatalyzed equilibration of hexamethyl disiloxane with octamethylcyclotetrasiloxane is similarly enhanced by dimethyl sulfoxide. The equilibration occurs rapidly at 80°C. with 0.01% of potassium hydroxide and 1% of dimethyl sulfoxide, but does not proceed at a measurable rate with potassium hydroxide alone. The combination of 0.01% potassium hydroxide and 1% dimethyl sulfoxide is more effective than 0.1% of tetramethylammonium hydroxide. The large accelerating effect of the sulfoxide is believed to be due to solvation of the cation, which promotes ionization of the metal silanolate, increasing the concentration of silanolate anions.     

Chemistry of the phenoxathiins and isosterically related heterocycles. XXXIII . The influence of intramolecular sulfur-nitro group interactions on the reactivity at sulfur

Nitro-groups positioned ortho to thio-esters have been shown to engage in strong, non-bonded intramolecular interactions between the sulfur atom and one of the nitro-group oxygens. The effect of the sulfur-nitro group oxygen interaction on the chemical reactivity at the sulfur atom of 9-nitro-1-azaphenoxathiin is reported. Conditions which normally produce the sulfone exclusively have been shown to yield the sulfoxide with only a minimal quantity of the sulfone produced. Protracted periods of reflux are required to produce the sulfone from the sulfoxide.     

Application of heme-containing biocatalysts for oxidation and determination of organosulfur compounds

The conditions of the oxidation of dibenzothiophene and aliphatic phenothiazines (promazine and chlorpromazine) in the presence of heme-containing biocatalysts (such as horseradish peroxidase and hemoglobin) have been optimized. It has been demonstrated that hemoglobin is an efficient catalyst for the fast and selective conversion of dibenzothiophene to the corresponding sulfoxide (yield is 91 ± 2% in 5 min); horseradish peroxidase is a more promising catalyst for the oxidation of phenothiazines. The effect of polar organic solvent (dimethyl sulfoxide) on the kinetics parameters of the reaction of oxidation of promazine in the presence of heme-containing biocatalysts has been studied. Procedures of determining phenothiazines based on spectrophotometric control of the rate of their oxidation have been developed. The applicable concentration ranges for the determination of promazine and chlorpromazine using horseradish peroxidase in aqueous medium were 10–100 μM and 10–200 μM respectively, and 20–500 μM for the determination of promazine in the presence of 10 vol % of dimethyl sulfoxide.     

Kinetic studies on the oxidation of aryl methyl sulfides and sulfoxides by dimethyldioxirane; absolute rate constants and activation parameters for 4-nitrophenyl methyl sulfide and sulfoxide

The oxidations of methyl 4-nitrophenyl sulfide and sulfoxide by dimethyldioxirane, in acetone and mixtures of acetone with water, methanol, acetonitrile and hexane, have been followed by UV-Vis spectroscopy to monitor the decay of the substrates. The data show that, under all the conditions studied, both oxidations obey second-order kinetics. Grunwald-Winstein and Kamlet-Taft analyses of the influence of solvents on the second-order rate constants have been used to obtain mechanistic information on the two reactions. Activation parameters for the two oxidations in acetone and aqueous acetone have been calculated from rate constants for reactions in the temperature range 283-313 K and compared with those from sulfide and sulfoxide oxidations with other oxidants. For sulfoxide oxidations in acetone and 1-20% v/v water in acetone, the results support a concerted nucleophilic displacement by sulfur of oxygen from dimethyldioxirane with the rate being dependent on the solvent's polarity. Sulfide oxidations in acetone and 1-5% v/v water in acetone also proceed by a concerted mechanism. However, in the most polar solvent system studied, 20% v/v water in acetone, the mechanism changes in favour of a two-step reaction involving a betaine intermediate. Importantly, the sulfide oxidation shows a different solvent dependence to that of the sulfoxide, with the rate of oxidation being determined by the hydrogen bond donor capacity and electron-pair donicity of the solvent.     

Synergistic solvent extraction of lutetium(III). Computer aided analysis

Synergism in the extraction of Lu(III) from thiocyanate solutions has been investigated using mixtures of bis-2-ethylhexyl sulfoxide (B2EHSO) and 2-thenoyltrifluoroacetone (HTTA) or di-n-octyl sulfoxide (DOSO) or tri-n-octylphosphine oxide (TOPO) in benzene. For comparison, the synergistic extraction of Lu(III) from perchlorate solutions has also been investigated with a mixture of B2EHSO and HTTA. These extraction data have been analyzed theoretically with the aid of a computer by taking into account complexation of the metal in the aqueous phase by inorganic ligands and plausible complexation in the organic phase. The equilibrium constants of the various product species have been deduced by non-linear regression analysis.     

Stereoselective oxidation of methyl phenyl sulfide in the presence of chiral ionic liquids

Several ionic liquids containing a chiral center either in the cation or in the anion have been prepared. They have been applied as catalysts and solvents for stereoselective oxidation of methyl phenyl sulfide to obtain the respective sulfoxide.     

Coordination chemistry of the solvated silver(I) ion in the oxygen donor solvents water, dimethyl sulfoxide, and N,N'-dimethylpropyleneurea

The hydrated and dimethyl sulfoxide and N,N'-dimethylpropyleneurea solvated silver(I) ions have been characterized structurally in solution by means of extended X-ray absorption fine structure (EXAFS) and large-angle X-ray scattering (LAXS). The coordination chemistry of the hydrated and dimethyl sulfoxide solvated silver(I) ions has been reevaluated because of different results from the EXAFS and LAXS methods reported previously. Consistent results are obtained with a linearly distorted tetrahedral model with two short and approximately two long Ag-O bond distances: mean Ag-O bond lengths of 2.32(1) and 2.54(1) A for the hydrate, 2.31(1) and 2.48(2) A for the dimethyl sulfoxide solvate, and 2.31(1) and 2.54(2) A for the N,N'-dimethylpropyleneurea solvate, in solution.     

Acidic properties of flavonoid compounds and the choice of solvent for performing potentiometric analysis

In order to choose a solvent for performing potentiometric titration, the relative acidities of 22 flavonoids have been studied in water, methanol, acetone, dimethylformamide, and dimethyl sulfoxide. It has been established that the conditions of titration improve on passing from water in the following sequence of organic solvents: methanol < dimethylformamide < acetone < dimethyl sulfoxide.Kharkov Scientific-Research Institute of Pharmaceutical Chemistry. Translated from Khimiya Prirodnykh Soedinenni, No. 2, pp. 180–186, March–April, 1980.     

C−H Coupling Reactions Directed by Sulfoxides: Teaching an Old Functional Group New Tricks

Sulfoxides are classical functional groups for directing the stoichiometric metalation and functionalization of C?H bonds. In recent times, sulfoxides have been given a new lease on life owing to the development of modern synthetic methods that have arisen because of their unique reactivity. They have recently been used in catalytic C?H activation proceeding via coordination of an internal sulfoxide to a metal or through the action of an external sulfoxide ligand. Furthermore, sulfoxides are able to capture nucleophiles and electrophiles to give sulfonium salts, which subsequently enable the formation of C?C bonds at the expense of C?H bonds. This Review summarizes a renaissance period in the application of sulfoxides arising from their versatility in directing C?H functionalization.     

Reinvestigation of the photolysis of aryl-substituted disilanes in the presence of dimethyl sulfoxide

The photolysis of aryl-substituted disilanes in the presence of dimethyl sulfoxide has been studied. Product studies, labelling experiments, and quantum yields have been carried out. Possible mechanisms are discussed.     

Enzyme-catalysed oxygenation and deoxygenation routes to chiral thiosulfinates

Enantioenriched thiosulfinates have been obtained by dioxygenase- and chloroperoxidase-catalysed oxidation of 1,2-disulfides and dimethyl sulfoxide reductase-catalysed deoxygenation.     

Luminescent Properties of Europium(III) Complexes with Quinaldic Acid and Sulfur–Containing Neutral Ligands

The luminescent heteroligand complexes of europium(III) with quinaldic acid and sulfur-containing neutral ligands Eu(Quin)3∙D∙3H2O (Quin–quinaldic acid, D–dimethyl sulfoxide or dihexyl sulfoxide) and Eu(Quin)3∙3H2O have been obtained. Their composition and structure have been determined. The thermal and spectral-luminescent properties of the heteroligand europium(III) complexes have been studied. The quinaldate ion has been found to coordinate to the europium(III) ion as a bidentate ligand. The Stark structure of 5D0–7Fj (j = 0, 1, 2) transitions in the low-temperature luminescence spectra of the europium(III) complexes has been analyzed