Kinetics and mechanism of methylthiomethyl acetate conversion into bis(methylthio)methane

Methylthiomethyl acetate can be rapidly and quantitatively converted into bis(methylthio)methane via an acid-catalyzed reaction under mild conditions. This conversion in the system benzene-aqueous sulfuric acid is interpreted in terms of a complex scheme of consecutive and parallel steps. It begins with the hydrolysis of the ester by the mechanisms A _AC2 and A _AL1 (in Ingold’s terminology), and the subsequent interactions involve intermediate products. The kinetics of the process is analyzed. A procedure for the synthesis of bis(methylthio)methane from dimethyl sulfoxide is suggested.     

Isomerism of bis(7-azaindolyl)methane

Three isomers of bis(7-azaindolyl)methane have been synthesized and fully characterized. Isomers 1 and 2 contain 7-azaindolyl groups that are bound to the CH(2) group through nitrogen atoms. However, 1 contains two "normal" 7-azaindolyl groups, whereas 2 contains both a normal 7-azaindolyl group and a tautomer form of 7-azaindolyl. The third isomer 4 contains two 7-azaindolyl groups that are bound to the CH(2) group through the carbon atom at the position-3. These three isomers show distinct absorption and emission spectra, attributable to the different forms of 7-azaindolyl groups in the isomers, as indicated by the results of ab initio calculations. [structure: see text]     

Extraction of uranium(VI) by bis(hexylsulfinyl)methane

The extraction of uranium(VI) with bis(hexylsulfinyl)methane (BHxSM) from nitric acid aqueous solution has been investigated. It was found that the extraction increased with increasing nitric acid concentration up 8.5 mol/l and then decreased. Extraction distribution ratio also increased with the bis(hexylsulfinyl)methane concentration. The extraction species appear to be UO₂(NO₃)₂ ^.2BHxSM. The influences of temperature, salting-out concentration and oxalate concentration on the extraction equilibrium were also investigated, and the enthalpy of the extraction reaction was obtained. The result shows that the reaction of uranium(VI) extraction with BHxSM is an exothermic one.     

Extraction of uranium(VI) with bis(octylsulfinyl)methane

The liquid-liquid extraction of uranium(VI) from aqueous nitric acid with bis(octylsulfinyl)methane (BOSM) has been studied over a wide range of conditions. The extracted species appear to be UO₂(NO₃)₂·2BOSM. It was found that the extraction increased with increasing nitric acid concentration up to 8.5 mol/l and then descreased. Extraction also increased with increasing extractant concentration. The influence of temperature and salting-out agent concentration on the extraction equilibrium has also been investigated, and the enthalpy of the extraction reaction was estimated.     

Structure and reactivity of bis(iodozincio)methane solution

Bis(iodozincio)methane, which has been shown to be an efficient reagent for organic synthesis, is obtained as THF solution. The structural information about the reagent as THF solution was corrected by small angle neutron scattering and by anomalous X-ray scattering. Those scattering experiments implied that the prepared bis(iodozincio)methane exists without forming any oligomer or aggregate. A coordination of tetrahydrothiophene to bis(iodozincio)methane enhances the nucleophilicity of the reagent and stabilizes its monomeric structure in the solution.     

The cyclometallation of bis(di-p-methylbenzylphosphino)methane

The new diphosphine (4-MeC₆H₄CH₂)₂PCH₂P(4-MeC₆H₄CH₂)₂, L, was reacted with [MnMe(CO)₅] to give the novel cyclometallated compound [Mn{(4-MeC₆H₃CH₂)(4-MeC₆H₄CH₂)PCH₂P(4-MeC₆H₄CH₂)₂}(CO)₃], as the mer isomer, and with the ligand in a terdentate [C,P,P] fashion.     

Transition metal complexes of bis(diphenylphosphine oxide)methane

Complexes of bis(diphenylphosphine oxide)methane with Fe(III), Ni(II), Co(II), Cu(II) and Zn(II) have been prepared and characterized. Experimental data are in support of chelation by the ligand to give 6-coordinate metal ions. The properties of the complexes are similar to those for the corresponding complexes of octamethylpyrophosphoramide.     

Kinetics of uranium(VI) extraction by bis(octylsulfinyl)methane

The kinetics and mechanism of uranium(VI) extraction from nitric acid solution by bis(octylsulfinyl)methane (BOSM) are studied with the method of stationary interface cell. The effects of temperature, extractant and nitric acid concentrations are discussed. The results showed that the extraction process is controlled by the following reaction: UO₂(NO₃)₂ + BOSM_(i)⇄_k1 ^k-1UO₂(NO₃)₂BOSM_(i). The variation of enthalpy associated with the extraction is -22.1±2.1 kJ/mol. This revised version was published online in July 2006 with corrections to the Cover Date.     

Reaction of bis (2-oxocyclohexyl)methane with hydrogen selenide

Bis (2-oxocyclohexyl) methane reacts with hydrogen selenide in polar solvents without a catalyst to give a product of nucleophilic addition of hydrogen selenide at one of the carbonyl groups, which exists in the form of three equilibrium forms, viz., 2-hemolselenolcyclohexyl-2-cyclohexanonylmethane, perhydroselenoxanthene-11,13-diol, and perhydro-11-xanthenol-13-selenol. The latter under the influence of an alcohol solution of alkali form 2,3-tetramethylenebicyclo[3.3.1]nonanon-9-ol, with hydrogen chloride; they react with hydrogen chloride to give sym-octahydroselenoxanthene, and trifluoroacetic acid converts them to a mixture of sym-octa-hydroselenoxanthylium trifluoroacetate and perhydroselenoxanthene. The trifluoroacetate reacts with perchloric acid to give sym-octahydroselenoxanthylium perchlorate.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 640–642, May, 1981.     

Complexes of lanthanide nitrates with bis(diphenylphosphino)methane dioxide

The reactions of lanthanide nitrates, Ln(NO(3))(3), with bis(diphenylphosphino)methane dioxide, Ph(2)P(O)CH(2)P(O)Ph(2) (L), lead to complexes with three distinct classes of structure. At low ratios of Ln:L (<1:1.5) in acetonitrile the ionic complexes [Ln(NO(3))(2)L(2)](+)[Ln(NO(3))(4)L](-) (Ln = Pr, Eu) have been isolated. When carried out with a 1:2 or higher ratio in ethanol the reaction yields Ln(NO(3))(3)L(2) (Ln = La,Ce) and [Ln(NO(3))(2)L(2)H(2)O](+)[NO(3)](-) (Ln = Nd, Gd, Ho). Geometrical isomerism is found for the cations [Ln(NO(3))(2)L(2)H(2)O](+) and is attributed to the extent of hydrogen bonding to the coordinated water. Ligand redistribution occurs on heating in the solid state giving yellow solids in all cases. Crystallization of these materials from ethanol or acetonitrile gives [Ln(NO(3))L(3)](2+).2[NO(3)](-), which have been structurally characterized for Ln = Gd and Yb. Electrospray mass spectra indicate that extensive ligand exchange reactions occur in solution.     

Synthesis and characterization of copper(II) complexes of nonfacially coordinating heteroscorpionate ligands (4-carboxyphenyl)bis(3,5-dimethylpyrazolyl)methane and (3-carboxyphenyl)bis(3,5-dimethylpyrazolyl)methane

Complexes of Cu(II) derived from two new nonfacially coordinating heteroscorpionate ligands, (4-carboxyphenyl)bis(3,5-dimethylpyrazolyl)methane (L4c) and (3-carboxyphenyl)bis(3,5-dimethylpyrazolyl)methane (L3c), have been synthesized and characterized by X-ray diffraction, ESI-MS, IR, and UV-vis spectroscopy, electrochemistry, and magnetic susceptibility. The use of these new complexes as building blocks for the construction of supramolecular architectures is discussed.     

The molecular structure of [dimethyl(phenyl)silyl]tris(trimethylsilyl)methane

The structure of the crowded molecule (Me₃Si)₃C(SiMe₂Ph) has been determined by single crystal X-ray diffraction. The steric strain manifest itself mainly in lengthening of the Me₃SiC and Me₂PhSiC bonds (average length 1.920(6) $\text{,ac>A}\text{?}$) and closing up of the CSiC angles within the Me₃Si and Me₂PhSi groups (average 105.2(10)°), with correspondingly large C(1)SiC angles (113.5(13)°; C(1) is the central carbon atom).