Bifunctional compounds from reaction of alkoxy hydroperoxides with metal salts

Alkoxy hydroperoxides, obtained by ozonizing olefins in alcoholic solution, were treated with ferrous sulfate. C-C bond scission and radical formation was followed by dimerization of the radicals formed. Ozonides reacted similarly. Acyclic and cyclic olefins, including a cyclic enol ether, gave rise to a range of ,ω-disubstituted products in modest yields. By using ferric chloride, ω-chloro esters were obtained from the alkoxy hydroperoxides derived from olefinic esters.     

Synthesis of pyridinium salts by the reaction of α, β-unsaturated ketones,primary amines,and compounds with labile hydrogen atoms

The reaction of , -unsaturated ketones or Mannich bases of ketones with primary aromatic amines and ketones (monoketones or dimedone) in the presence of polyhalo-alkanes leads to pyridinium, 5,6,7,8-tetrahydroquinolinium, or sym-octahydroacridinium salts. The reaction of benxalcyclohexanone with primary aromatic amines and malonodinitrile makes it possible to obtain 2-amino-3-cyano-5,6,7,8-tetrahydroquinolinium salts.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1060–1064, August, 1985.     

The role of hydrogen atoms in CIDNP effects in the reaction of diisobutylaluminum hydride with CCl4

Integral polarization of chloroform, methylene dichloride, and pentachloroethane was observed in the¹H NMR spectra during the exothermal reaction of a 1M solution of Bu₂ ⁱ in 1,4-dioxane with CCI₄. CIDNP was shown to appear in the diffusion radical pair of the hydrogen atom and trichloromethyl radical. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2097–2099, October, 1998.     

The reaction of hydrogen atoms with 1-butanethiol and thiolane the role of chemically activated 1-butanethiol

The reaction of 1-butanethiol with hydrogen atoms has been studied at temperatures of 295° and 576° K under the pressure of 660 Pa, using a conventional discharge-flow apparatus. The reaction products (besides hydrogen sulfide and methane) under the low conversion range (～10%) consisted mainly of n-butane, 1-butene, and propylene-propane, with the relative yields of 70, 25, and 5% at 295° K and 25, 50, and 10% at 576°K. Analysis of kinetic equations by numerical integration indicates that the following initial steps are consistent with the experimental results: where the following expressions have been derived for k₁ and k₂: The subsequent reaction of the butylthio radical with hydrogen atoms leads to the chemically activated 1-butanethiol which either stabilizes to 1-butanethiol or decomposes to 1-butene and hydrogen sulfide, depending on the experimental conditions. A similar analysis of the data on the thiolane-H system has yielded the following rate parameters for the initial step to form the 4-mercapto-1-butyl radical: .     

Energetics and kinetics of the reaction of HOCO with hydrogen atoms

The potential energy surface for the reaction of HOCO radicals with hydrogen atoms has been explored using the CCSD(T)/aug-cc-pVQZ ab initio method. Results show that the reaction occurs via a formic acid (HOC(O)H) intermediate, and produces two types of products: H(2)O+CO and H(2)+CO(2). Reaction enthalpies (0 K) are obtained as -102.0 kcalmol for the H(2)+CO(2) products, and -92.7 kcalmol for H(2)O+CO. Along the reaction pathways, there exists a nearly late transition state for each product channel. However, the transition states locate noticeably below the reactant asymptote. Direct ab initio dynamics calculations are also carried out for studying the kinetics of the H+HOCO reaction. At room temperature, the rate coefficient is predicted to be 1.07x10(-10)cm(3) molec(-1) s(-1) with a negligible activation energy E(a)=0.06 kcalmol, and the branching ratios are estimated to be 0.87 for H(2)+CO(2), and 0.13 for H(2)O+CO. In contrast, the product branching ratios have a strong T dependence. The branching ratio for H(2)O+CO could increase to 0.72 at T=1000 K.     

Chemical synthesis with metal atoms: the reaction of chromium and nickel atoms with styrene

The preparation of C₈H₈Cr(CO)₃ (or C₈H₈Cr(PF₃)₃) and polystyrenechromium tricarbonyl (or polystyrenechromium tris(trifluorophosphine) from chromium atoms, styrene and carbon monoxide (or trifluorophosphine) is described; nickel atoms and styrene produce tristyrenenickel, which reacts with α,α′-bipyridyl to yield bipyridylstyrenenickel.     

Theoretical study on the reaction of hydrogen atoms with aniline

The reaction of aniline with hydrogen atom is investigated herein using the hybrid meta-DFT functional of BB1 K. Hydrogen atom is found to preferentially add at an ortho position. However, the fate of the o-(C₆H₅NH₂)H adduct is found to be solely the deactivation of the initial addition channel. The rate constant for the abstraction channel (C₆H₅NH₂ + H → C₆H₅NH + H₂) is fitted by the expression 1.10 × 10⁻¹¹ exp(−4,200/T) cm³ molecule⁻¹ s⁻¹. Our calculated rate constant for the abstraction channel agrees very well with the available experimental measurements. Satisfactory agreement is found between calculated and experimental measurements for the displacement channel (C₆H₅NH₂ + H → C₆H₆ + NH₂). Our detailed analysis for the corresponding displacements in toluene and phenol suggests that the three systems exhibit similar behavior with regard to the relative importance of abstraction and displacement channels.     

Near Hartree-Fock limit study of the linear chain of hydrogen atoms

The linear, equidistant chain of hydrogen atoms has been studied with the aid of the crystal orbital method. Extended gaussin basis sets have been used, with the aim to obtain near Hartree—Fock limit ground state properties. The metallic type and the broken symmetry type solution yielded energies of ?0.5361 and ?0.5372 hartree, respectively, for the total energy per hydrogen atom. These values are estimated to be at most 0.5 millihartree above the Hartree-Fock limit. The corresponding values for the equilibrium distance r_e are 1.840 and 1.843 bohr, respectively.     

Reduction of unsaturated compounds with hydrogen transfer from alcohol in the presence of transition metal salts

Conclusions The reduction of some unsaturated compounds was accomplished in the presence of transition metal salts using alcohol as the hydrogen donor.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5. pp. 1180–1181, May, 1972.     

Chemiluminescence of CaH and AIH in the reaction of the metal atoms and formaldehyde

Chemiluminescence from the reaction of calcium and aluminum with various hydrogen containing compounds in a flowing gas system and in a heat pipe oven are described. Red chemiluminescence of CaH was observed in the reaction of calcium, and weak chemiluminescence of AlH was seen in the reaction of aluminum with formaldehyde (H₂CO). It is proposed that a reaction between metal atoms and formaldehyde may be used as a source of diatomic metallic hydrides.     

A theoretical analysis of the reaction between hydrogen atoms and isocyanic acid

Using BAC-MP4 potential-surface parameters, supplemented by an MP2 normal-mode analysis at one transition state, and statistical theoretical methods, we have computed thermal rate coefficients for the reactions, and Over the entire temperature range considered, 300 K < T < 3300 K, reaction (2) is the dominant product channel. The theoretical predictions are in excellent agreement with the experimental results available for k₂ and k_?1, the rate coefficient for the reverse of reaction (1). Modified Arrhenius expressions are given for k₁, k_?1, and k₂. In addition, we identify and discuss a weakness in utilizing a Hartree-Fock normal-mode analysis in the prediction of k₂. The present result for k₂ is much smaller than that used in the initial modeling of the RAPRENO_x process. The implications of this are discussed.     

Surface processes in hydrogen permeation through metal membranes

The phenomenon of hydrogen permeation through metals is considered as a complex of interphase and diffusion processes. Basic principles of application of the hydrogen permeation technique to studies of various stages of hydrogen interaction with metals are formulated. An analysis is made of possible errors of the permeation technique when used to measure the characteristics of hydrogen diffusion through metals originating from the finite rate of the interphase processes. The permeation of nonequilibrium and corrosion-produced hydrogen through metal membranes, and the hydrogen permeability of multilayer systems are considered.     

Stabilization of surface reaction intermediates by added metal atoms on metal surfaces of low free energy

Dynamic restructuring of the Ag(111) surface occurs during the reaction of sulfur dioxide with Ag(111)-p(4 x 4)-O at 300 K, resulting in the incorporation of added silver atoms into the unit cells of both adsorbed sulfite and sulfate. This result clearly demonstrates that incorporation of metal atoms into the structures of adsorbates and reaction intermediates is not restricted to more open, higher free energy single crystal planes. These observations indicate that the participation of added metal atoms must be considered in the theoretical treatment of metal catalyzed reactions.