Lithiation of the Tin-containing Sulfone Me3SnCH2CH2CH2SO2C6H4CH3-4

The tin-containing sulfide Me₃Sn(CH₂)₃-S-C₆H₅CH₃-4 obtained by photoaddition of 4-toluene- thiol to allyltrimethyltin was oxidized with hydrogen peroxide to synthesize the tin-containing sulfone Me₃Sn(CH₂)₃-SO₂-C₆H₄CH₃-4, the tin and sulfur atoms in which are separated by a trimethylene bribge. Treatment of the sulfone with butyllithium gave a first tin-containing lithium salt having a red-brown color. The exchange reaction of this salt with methyl iodide resulted in formation of two new isomeric tin-containing sulfones Me₃SnCH₂CH₂CH(CH₃)-SO₂-C₆H₄CH₃ and Me₃Sn(CH₂)₃-SO₂-C₆H₄CH₂CH₃ identified by ^1HNMR spectroscopy. The latter result implies that the tin-containing sulfone is lithiated both by the methylene group adjacent to the sulfonyl group and by the toluene methyl group.     

GF Calculations for some tricyclic molecules: C3H6, C3H4, C2H4NH,C2H4O and C2H4S

We have functions expressed as antisymmetrized products of strongly orthogonal geminals have been evaluated for some three membered ring molecules. GF results are compared with previously computed SCF-MO results, obtained employing the same atomic basis. Transferability features of bonds and inner shells are shown.     

Isotropic C6, C8 and C10 interaction coefficients for CH4, C2H6, C3H8, n-C4H10 and cyclo-C3H6

The non-empirical generalized Kirkwood, Unsöld, and the single-Δ Unsöld methods (with double-zeta quality SCF wave-functions) are used to calculate isotropic dispersion (and induction) energy coefficients C_2n, with n ? 5, for interactions involving ground state CH₄, C₂H₆, C₃H₈, n-C₄H₁₀ and cyclo-C₃H₆. Results are also given for the related multipole polarizabilities α_l, multipole sums S₁/(0) and S₁(?1) which are evaluated using sum rules, and the permanent multipole moments. for l = 1 (dipole) to l = 3 (octupole). Estimates of the reliability of the non-empirical methods, for the type of molecules considered, are obtained by a comparison with accurate literature values of α₁S₁(?1) and C₆. This, and the asymptotic properties of the multipolar expansion of the dispersion energy, the use to discuss recommended representation for the isotropic long range interaction energies through R^?10 where R is the intermolecular separation.     

Endohedral complexes of fullerene-like silica molecules with H2O, CH4, and CH3NH2 molecules

The possibility of formation of (SiO₂)₆₀@H₂O, (SiO₂)₆₀@CH₄, and (SiO₂)₆₀@CH₃NH₂ endohedral complexes was studied by the density functional (DFT) method (B3LYP exchange correlation functional, 6-31G** basis). The penetration of these molecules into the cavity of fullerene-like silica molecules is hindered by high activation barriers, which ensures the stability of the complexes formed during the synthesis of these molecules.     

Hydrothermal Synthesis and Crystal Structure of a New Phosphonate： {[Cu（1,10-phen）]2-（H2O3PCH2C6H4C6H4CH2PO3H）2-（HO3PCH2C6H4C6H4CH2PO3H） }n

1 INTRODUCTION Metal organophosphonates have attracted considerable attention for over three decades due to their potential or practical applications, include- ing ion exchanges[1, 2], molecular sensors[3] and optics[4, 5]. Recently, a number of porous m…     

Total cross sections for electron scattering by polyatomic molecules at 10–1000 eV: C2H2, C2H4, C2H6, C3H6, C3H8 and C4H8

A model complex optical potential (composed of static, exchange, polarization and absorption terms) is employed to calculate the total (elastic and inelastic) electron-atom scattering cross sections from the corresponding atomic wave function at the Hartree-Fock level. The total cross sections (TCS) for electron scattering by their corresponding molecules (C₂H₂, C₂H₄, C₂H₆, C₃H₆, C₃H₈ and C₄H₈) are firstly obtained by the use of the additivity rule over an incident energy range of 10–1000 eV. The qualitative molecular results are compared with experimental data and other calculations wherever available, good agreement is obtained in intermediate-and high-energy region.     

Ab initio vibrational state calculations with a quartic force field: applications to H2CO, C2H4, CH3OH, CH3CCH, and C6H6

For polyatomic molecules, n-mode coupling representations of the quartic force field (nMR-QFF) are presented, which include terms up to n normal coordinate couplings in a fourth-order polynomial potential energy function. The computational scheme to evaluate third-and fourth-order derivatives by finite differentiations of the energy is fully described. The code to generate the nMR-QFF has been implemented into GAMESS program package and interfaced with the vibrational self-consistent field (VSCF) and correlation corrected VSCF (cc-VSCF) methods. As a demonstration, fundamental frequencies have been calculated by the cc-VSCF method based on 2MR-QFF for formaldehyde, ethylene, methanol, propyne, and benzene. The applications show that 2MR-QFF is a highly accurate potential energy function, with errors of 1.0-1.9% relative to the experimental value in fundamental frequencies. This approach will help quantitative evaluations of vibrational energies of a general molecule with a reasonable computational cost.     

Unimolecular reactions of the isolated immonium ions CH3CH = NH+C4H9, CH3CH2Ch = NH+C4H9 and (CH3)2C = NH+C4H9

The reactions of ten metastable immonium ions of general structure R¹R²C?NH⁺C₄H₉ (R¹ = H, R² = CH₃, C₂H₅; R¹ = R² = CH₃) are reported and discussed. Elimination of C₄H₈ is usually the dominant fragmentation pathway. This process gives rise to a Gaussian metastable peak; it is interpreted in terms of a mechanism involving ion-neutral complexes containing incipient butyl) cations. Metastable immonium ions ontaining an isobutyl group are unique in undergoing a minor amount of imine (R¹R²C?NH) loss. This decomposition route, which also produces a Gaussian metastable peak, decreases in importance as the basicity of the imine increases. The correlation between imine loss and the presence of an isobutyl group is rationalized by the rearrangement of the appropriate ion-neutral complexes in which there are isobutyl cations to the isomeric complexes containing the thermodynamically more stable tert-butyl cations. A sizeable amount of a third reaction, expulsion of C₃H₆, is observed for metastable n-C₄H₉ ⁺NH?CR¹R² ions; in contrast to C₄H₈ and R¹R²C?NH loss, C₃H₆ elimination occurs with a large kinetic energy release (40–48 kJ mol^?1) and is evidenced by a dish-topped metastable peak. This process is explained using a two-step mechanism involving a 1,5-hydride shift, followed by cleavage of the resultant secondary open-chain cations, CH₃CH⁺ CH₂CH₂NHCHR¹R².     

Kinetics of Depletion of Electronically Excited Ti Atom by CH4, C2H2, C2H4 and C2H6

The kinetics of depletion of ground state Ti(a³F) and electronically excited state Ti(a⁵F) upon interactions with CH₄, C₂H₂, C₂H₄, and C₂H₆ are studied in a fast-flow reactor at a He pressure of 0.70 Torr. No depletion of ground state Ti(a³F) was observed upon interaction with all hydrocarbons studied here. Two alkanes, CH₄ and C₂H₆, were also quite inert for depletion of the excited state Ti(a⁵F), On the other hand, C₂H₂ and C₂H₄ deplete the excited state Ti(a⁵F) very efficiently. Rate constants were determined to be (266 ± 86) and (476 ± 88) × 10^?12 cm³s^?1 for Ti(a⁵F) + C₂H₄ and Ti(a⁵F) + C₂H₂, respectively. These large rate constants compared with the ground state Ti were explained by an electron donor-acceptor interaction model that works in the interaction between C₂H₄ or C₂H₂ and the excited state with unfilled 4s orbital.     

A shock-tube study of the kinetics of reaction of hydroxyl radicals with H2, CO,CH4, CF3H,C2H4, and C2H6

Concentration-time profiles have been measured for hydroxyl radicals generated by the shock-tube decomposition of hydrogen peroxide in the presence of a variety of additives. At temperatures close to 1300°K the rate constants for the reaction are found to be in the ratio 0.18:0.19:0.59:1.00:2.33:2.88 for the additives CO:CF₃H:H₂:CH₄:C₂H₄:C₂H₆, respectively.     

Diskussion Intramolekularer Wechselwirkungen an RC6H4(CH3)2SiF-, RC6H4(CH3)2SiOCH3-, RC6H4O(CH3)2SiF-, RC6H4OSi(CH3)3- und (CH3)3MF- [M  C,Si, Ge,Sn] Verbindungen

Chalcogenide Glasses with Organic Components. I. Glasses of the Selenium-Arsenic-Bromine-Azobenzene System New glasses were prepared by melting suitable glasses of the system Se? As? Br and of Bis(selenenylbromido)-azobenzene, and cooling them subsequently. Azobenzene groups are connected with the inorganic glass by selenium-carbon bonds. These substances represent the link between polymers as part of the organic chemistry and inorganic glasses. The structures of these products are discussed on the basis of thermal, conductivity, and infrared spectroscopic studies and of density measurements.     

Reactions of Cl2P3/2: Absolute rate constants for reaction with H2, CH4, C2H6, CH2Cl2, C2Cl4, and c?C6H12

The absolute rate constants have been measured for several gas-phase chlorine atom-molecule reactions at 25°C by resonance fluorescence. These reactions and their corresponding rate constants in units of cm³ mole^?1 sec^?1 are: The effects of varying the substrate pressure, total pressure, light intensity and chlorine-atom source on the value of the bimolecular rate constants have been investigated for all these reactions. Conditions under which no competing side reaction occurs were established and the reported rate constants were measured under these conditions. For reactions (2), (5), (6), (7), and 8, there is a discrepancy of a factor of two between the rate constants measured in this work and values in the literature; it is suggested that this is due to an error in the previously measured value of k/k upon which the relative measurements in the literature ultimately depend.     

Accurate ab initio predictions of ionization energies of hydrocarbon radicals: CH2, CH3, C2H, C2H3, C2H5, C3H3, and C3H5

The ionization energies for methylene (CH2), methyl (CH3), ethynyl (C2H), vinyl (C2H3), ethyl (C2H5), propargyl (C3H3), and allyl (C3H5) radicals have been calculated by the wave-function-based ab initio CCSD(T)/CBS approach, which involves the approximation to the complete basis set (CBS) limit at the coupled-cluster level with single and double excitations plus a quasiperturbative triple excitation [CCSD(T)]. When it is appropriate, the zero-point vibrational energy correction, the core-valence electronic correction, the scalar relativistic effect correction, the diagonal Born-Oppenheimer correction, and the high-order correlation correction have also been made in these calculations. The comparison between the computed ionization energy (IE) values and the highly precise experimental IE values determined in previous pulsed field ionization-photoelectron (PFI-PE) studies indicates that the CCSD(T)/CBS method is capable of providing accurate IE predictions for these hydrocarbon radicals achieving error limits well within +/-10 meV. The benchmarking of the CCSD(T)/CBS IE predictions by the PFI-PE experimental results also lends strong support for the conclusion that the CCSD(T)/CBS approach with high-level energy corrections can serve as a valuable alternative for reliable IE determination of radicals, particularly for those radicals with very unfavorable Franck-Condon factors for photoionization transitions near their ionization thresholds.     

Marron-weare variational computation of energy differences for motions of C2H6, B2H6, CH3CH inf2 sup+ , and CH3BH2

The passage of D_3dC₂H₆ and B2H6 toward a D₂ h bridged structure, and the motion of a methyl proton maintaining C symmetry in C₂H _inf5 ^sup+ and CH₃BH₂ are described by integral Hellmann-Feynman computations in a Frost floating spherical Gaussian basis. Marron and Weare's variational corrections to the integral Hellmann-Feynman formula forAE between statesA andB are evaluated with variational functions of the form η(ψ_A/S_AB-ψ_B)) used to refine the stateB. An analogous function ξ(ψ_B/S_AB-ψ_A) refines state A. Both η and ξ are chosen variationally to minimize Marron and Weare's functional. No obvious advantage of the variational method became apparent in this simple application.     

Ni基催化剂上CH4、C2H6和C2H4的裂解积炭性能

采用脉冲微反技术研究了添加半导体氧化物对Ni基催化剂上CH4、C2H6和C2H4的裂解积炭反应特性的影响。结果表明,n型半导体CeO2的添加降低了CH4和C2H6的积炭活性,而p型半导体Co3O4的添加则加速CH4和C2H6的裂解积炭;而对于与CH4和C2H6活化机制不同的C2H4分子的活化,上述影响机制正好相反,n型半导体CeO2的添加促进C2H4的裂解积炭反应,而p型半导体Co3O4的添加则抑制C2H4的裂解积炭反应。XPS分析表明,活性金属Ni与半导体氧化物之间存在的金属 半导体相互作用是这种影响机制的主要因素。     

Schwermetall-π-Komplexe. IX. Die Kettenpolymere [(1,2- (CH3)2C6H4BiCl3)2], [(1,3) (CH3)2C6H4BiCl3)2] und [(1,4- (CH3)2C6H4BiCl3)2]

Heavy Metal π-Complexes. IX. The Chain Polymers [(1,2- (CH₃)₂C₆H₄BiCl₃)₂], [(1,3- (CH₃)₂C₆H₄BiCl₃)₂] and [(1,4- (CH₃)₂C₆H₄BiCl₃)₂] In the crystal structures of the three solid state complexes (C₆H₄(CH₃)₂BiCl₃ (C₆H₄(CH₃)₂ = o-xylene: 1 , m-xylene: 2 , p-xylene: 3 ) quasi-dimeric units of almost undistorted, arene coordinated BiCl₃ fragments can be found that are further associated via additional Bi? Cl contacts to form one-dimensional polymeric chains. Whereas the chains of 2 and 3 are constituted by Bi₂Cl₂ four-membered rings only, further Cl-bridging in 1 leads to additional trigonal-bipyramidal arrangements with Bi atoms exhibiting coordination numbers of 3 + 3 + 1 and 3 + 2 + 1, respectively (prim. + sec. Cl contacts + arene). The arene-metal bonding is characterized by Bi-arene distances in the range from 297 – 306 pm, including ring slippages of 24 –41 pm and 73 pm with the Bi atoms being six and seven coordinated, respectively. The direction of this slipping with respect to the arene's methylation sites cannot be understood in terms of electronic influences but is shown to be caused by steric demands. The values IP₁ of the arenes prove to determine the colours of the complexes.