Condensed 1,3,5-triazepines—III : Derivatives of 4,5-dihydro-[1,3,5]triazepino[1,2-a]benzimidazole

Methods have been developed for the synthesis of 2-amino-1-(2-aminoethyl)-benzimidazoles 10. By ring closures with the aid of suitable C₁-components, derivatives 11a–c, 13–15 of the novel [1,3,5]triazepino[1,2-a] benzimidazole ring system have been obtained.     

Determination of thermodynamic properties of isotactic poly(1-butene) at infinite dilution using density and inverse gas chromatography

The partial molar volumes, V1(M), and the molar volume of isotactic crystalline low-molecular-weight poly(1-butene), iPBu-1, V1, have been calculated from the measured density of {iPBu-1 + solvent (n-hexane, n-heptane, n-nonane, n-decane, p-xylene, cyclohexane and chloroform)} systems. Some of the thermodynamic quantities were also obtained for the iPBu-1 with eight hydrocarbons (n-octane, n-decane, n-undecane, n-dodecane, n-tridecane, o-xylene, m-xylene, p-xylene) by the method of inverse gas chromatography at various temperatures. The weight fraction activity coefficients of the solvent at infinite dilution, omega2(infinity) and the Flory-Huggins thermodynamic interaction parameters, chi21(infinity), between polymer and solvents were determined. The partial molar free energy, deltaG2(infinity), the partial molar heat of mixing, deltaH2(infinity), at infinite dilution and the polymer solubility parameter, delta1, were calculated. Additionally, the (solid + liquid) binary mixtures equilibria, SLE, of iPBu-1 with three hydrocarbons (n-octane, n-decane and m-xylene) were studied by a dynamic method. By performing these experiments over a large concentration range, the T-x phase diagrams of the polymer-solvent systems were constructed. The excess Gibbs energy models were used to describe the nonideal behaviour of the liquid phase. The omega2(infinity) were determined from the solubility measurements and were predicted by using the UNIFAC FV model.     

The synthesis of (3,4,5,6-tetrahydro-4-oxo-2h-1,3-thiazin-2-yl)-alkanoic acids,their derivatives and some related compounds

5,6-Dihydro-2H-1,3-thiazin-4(3H)-ones 2–10 related to the natural antituberculytic Mycobacidine 1, have been synthesised. Some of the compounds of types 2,3 and 5 proved highly active in vitro against Mycobacterium tuberculosis typ. humanus (H₃₇R_v), but the in vitro activities are diminished or suspended in the presence of biotine.     

Kinetics of Oxidation of Organic Acids by Ammonium Nitrate

Kinetics of oxidation of some organic acids by ammonium nitrate was studied. Temperature dependences of the rate constants of acid oxidation were determined.     

Thermodynamic Analysis of Combustible Formulations Forming Gaseous Metals in Combustion Products

A thermodynamic analysis of the burning temperatures and products formed in combustion of formulations containing zinc or lead was made in relation to the elemental composition and total enthalpy of formation of the starting mixture in order to develop programs searching in the existing database for such formulations whose combustion will produce a prescribed fraction of a metal in gaseous state.     

Energetic potential of solid composite propellants based on CL-20-containing bimolecular crystals

The energetic potential of bimolecular crystals (BMCs) containing CL-20 as components of solid composite propellants (SCPs) was investigated. The experimental and calculated values of the standard enthalpies of formation are reported. The maximum heats of explosion, which correlate with the impact sensitivity, were calculated. The specific impulse values and the densities of SCPs based on an active binder, aluminum, and oxidizer (BMC + a small portion of ammonium dinitramide) were evaluated.     

Dispersion filter for spectral and spatial resolution of pure rotational Raman scattering

A new filtering technique for Raman spectroscopy utilizes atomic vapor to suppress strong elastic and Rayleigh scattering while simultaneously resolving individual rotational Raman lines. Filtered images capture high-resolution spectral information in one dimension and spatial resolution in the other dimension. The filter is based on resonance enhanced dispersion, where the index of refraction varies dramatically. In a simple prism geometry the vapor disperses incident radiation according to frequency. A mercury-vapor-based dispersion filter has been fabricated, modeled, and demonstrated to capture pure rotational Raman scattering from CO(2).     

The reaction of 2,5,5-triphenyl-2-oxazolin-4-one with phosphorus pentasulfide

2,5,5-Triphenyl-2-oxazolin-4-one (3), when refluxed with phosphorus pentasulfide in xylene, is transformed into N-(3-phenyl-2-benzo[b]thienyl)-thiobenzamide (7).     

Benzoxadiazocines,benzothiadiazocines and benzotriazocines-V : The synthesis of some 2-amino-6-methyl- and 2-amino-6-phenyl-5,6-dihydro-4h-3,1,6-benzothiadiazocines

A method is described for the synthesis of hydrochlorides of some type 8 title compounds in which the nucleophilicity of N-2 is reduced or completely lost so as to prevent ring contraction reactions and, as a result, making these compounds comparatively stable.     

The Dolbeault complex in infinite dimensions III. Sheaf cohomology in Banach spaces

We prove that the sheaf cohomology groups H ^q (Ω,?) vanish if Ω is a pseudoconvex open subset of a Banach space with unconditional basis, and q≥1. Oblatum 23-XII-1999 & 12-V-2000?Published online: 16 August 2000