Competition Kinetics of the Nonbranched-Chain Addition of Free Radicals to Olefins, Formaldehyde, and Oxygen

Five reaction schemes are suggested for the initiated nonbranched-chain addition of free radicals to the multiple bonds of alkenes, formaldehyde, and oxygen. The schemes include reactions competing with chain propagation through a reactive free radical. The chain evolution stage in these schemes involves three or four types of free radicals. One of them— , , , , or —is relatively low-reactive and inhibits the chain process by shortening of the kinetic chain length. Based on the suggested schemes, nine rate equations containing one to three parameters to be determined directly are set up using quasi-steady-state treatment. These equations provide good fits for the nonmonotonic (peaking) dependences of the formation rates of the molecular addition products (1 : 1 adducts) on the concentration of the unsaturated component in liquid homogeneous binary systems consisting of a saturated component (hydrocarbon, alcohol, etc.) and an unsaturated component (olefin, formaldehyde, or dioxygen). The unsaturated compound in these systems is both a reactant and an autoinhibitor generating low-reactive free radicals. A similar kinetic description is applicable to nonbranched-chain free-radical hydrogen oxidation. The energetics of the key radical-molecule reactions is considered.

Coexisting chloritoid and staurolite and the staurolite–chlorite isograd from the Agnew Lake area, Ontario, Canada

SummaryChloritoid and staurolite bearing rocks from the Agnew Lake area in northern Ontario were studied petrographically and with the electron microprobe. A staurolite–chlorite isograd is postulated, above which chloritoid and staurolite coexist in equilibrium, and a Schreinemakers-type petrogenetic grid is constructed to illustrate how the isograd might fit into a paragenetic sequence.The staurolites from the area are observed to be more ‘siderophile’ than the chloritoids and this suggests that the chlorite participating in the isograd reaction is prograde. This is confirmed in the ‘real’ isograd reaction:1.559ctd+5.000and+0.009rut+0.058ilm=0.881st+0.039chl+1.366qtz+1.040H2O the coefficients of which are calculated using the mineral analyses of the ideally univariant assemblage staurolite–chloritoid–chlorite–andalusite. Variations in the activity of the unsaturated component ZnO would affect the equilibrium temperature of the reaction and the reaction coefficients.

Some volatile constituents of terrestrial slaters

The common terrestrial dater, Porcellio scaber, yields a volatile extractive, slaterol, which comprises cis- and trans-dec-3-en-1-ol (80%), together with cis- and trans-non-3-en-1-ol and nonan-1-ol (5%). The remaining and unsaturated component of slaterol (A, 15%), which gives decan-1-ol on reduction, has yet to be characterized. An undescribed Armadillidium sp. yields a single constituent, octan-1-ol.

CHARACTERIZATION OF SCHIFF-POSITIVE SUBSTANCES IN ELASTIC FIBERS

Schiff-positive substances in clastic fibers have been separated on the basis of differences in reactivity with the reagent. Alkali-treated ligamentum nuchae powder contains a cerebroside which is removed by chloroform or pyridine. Also present are a plasmalogen-like compound which depends upon its unsaturated component for its reactivity, and a substance whose Schiff positivity is negated by prior treatment with iodine; both reactants are resistant to extraction techniques. Mercuric chloride or enzymatic hydrolysis releases an unsaturated fatty material, probably the aldehydic component of the clastin-bound plasmalogen-like compound. Elastin powder which has been treated with phenylhydrazine, iodine and bromine still gives a positive reaction with fuchsin-sulfurous acid. Rat aortic clastica, like ligamentum nuchac, contains a non-extractable plasmalogen like compound whose reactivity with Schiff's reagent depends Upon unsaturation in the molecule. Staining intensity is reduced by prior chloroform extraction, suggesting a glycolipid as was demonstrated for ligamentum nuchae.