The antiarrhythmic and antiinflammatory activity of a series of tricyclic pyrazoles

A series of tricyclic pyrazoles were prepared from intermediates available from steroid total synthesis and tested for antiarrhythmic and antiinflammatory activity.     

Kinetics and mechanism of the autoxidation of pentaerythrityl tetraheptanoate at 180–220°C

A kinetic and mechanistic study of the autoxidation of liquid pentaerythrityl tetraheptanoate (PETH) at 180–220°C has been carried out utilizing a stirred-flow reactor. The results are consistent with the occurrence of a chain reaction scheme similar to that proposed for n-hexadecane autoxidation, namely, the formation of monohydroperoxides by the intermolecular abstraction reaction (3), the formation of α,γ- and α,δ-dihydroperoxides and α,γ- and α,δ-hydroperoxyketones by intramolecular peroxy radical abstraction reactions (4) and (4*), the bimolecular termination of peroxy radicals, reaction (6), and the rapid conversion of α,γ-hydroperoxyketones to the corresponding cleavage acids and methyl ketones, reaction (7). Comparisons of various rate parameters for the n-hexadecane and PETH systems reveal that the values of k₇ and (k₃/H atom)/(2 k₆)^1/2 are within experimental uncertainties identical for the two systems at 180°C. The proposed reaction scheme includes the concurrent formation of hydroxy radicals and hydroperoxyketone species. The results of kinetic analysis and the experimentally observed isomer distributions of primary and secondary monohydroperoxide products at high and low oxygen pressures suggest that ≈60% of the hydrogen abstractions from PETH at high oxygen pressures occur by hydroxy radicals.     

Ion-selective electrodes responsive to chlorocobaltate(II) ions

The response characteristics of some electrodes sensitive to chlorocobaltate(II) ions are reported. The most reliable electrode, which showed near-Nernstian response in the range 10^-1–10^-4 M cobalt(II), was obtained by using a membrane consisting of 35% poly(vinyl chloride), 5% Aliquat chloride, and 60% of the blue oil obtained by extraction of cobalt with Aliquat-336, with conventional internal reference system.     

Qualitative and quantitative gas liquid chromatography of triglycerides.

This article reviews the methodology required for triglyceride analysis by gas liquid chromatography. Compositions of the animal and vegetable triglyceride mixtures to which this technique has been applied are summarized.     

Optical bistability in a gaussian cavity mode

The mean field treatment of dispersive and absorptive bistability for two-level atoms in an optical cavity is extended to account for the gaussian envelope of the cavity mode. The principal modification to the plane wave cavity case is the raising of the critical threshold for absorptive bistability as compared to thresholds for dispersive bistability.     

Aryl substituent effects upon the thermal isomerization of n-alkyl oxaziridines to nitrones

The results of a kinetic study of the thermal isomerization of oxaziridines derived from $\text{para}$-substituted C-arylaldimines and C-diarylketimines to the isomeric nitrones is reported.