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Photooxidation of cumene (isopropylbenzene) and pyridine in dilute solution in natural waters gives products characteristic of reactions with alkylperoxy (RO(2).) and hydroxyl (HO.) radicals. On the basis of the rates of formation of the products, the average concentrations of RO(2). and HO. are estimated to be about 10(-9) and 10(-17) mole per liter, respectively. The concentration of RO(2). is large enough that, for some classes of reactive chemicals, oxidation can be an important process in natural waters.

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synopsisRates of oxygen absorption and formation of oxidation products were determined in ?-initiated oxidations of thin films of high-and lowdensity polyethylene, atactic and isotactic polypropylene, and of three ethylene-propylene copolymers. Radiation yields G for 0 2 absorbed and formation of hydroperoxides depend on dose rates and decrease sharply with increasing ethylene content of the copolymers and moderately with increasing crystallinity of any base polymer. G values for dialkyl peroxide and carbonyl formation, and therefore for chain initiation and termination, do not change much with polymer composition and crystallinity and not at all with dose rates. A few experiments with atactic polypropylene and an amorphous ethylene-propylene copolymer, initiated by di-tert-butylperoxy oxdate, indicate that 37 mole-% of ethylene in the polymer increases the efficiency of initiation and the tendency toward crosslinking. 15,000 102,7008Crystallinity by heat of fusion; a,,, = 427,200; all measured on our film by Dr. J. R.Knox.

l-Acetyl-l-methylcyclohexane: bp 68-70°(7 mm) [lit.26 bp 80-8.5°(16 mm)]; 13.8 g (66% based upon 150 mmol of olefin) isolated; ir 1700 cm-1; nmr r 8.0 and 9.0 [sharp s, H3CCOCCH8]; vpc (130°a nd 150°) 18 showed a single compound. The 2,4-DNP had a melting point of 131-132°( lit.26 mp 132°) and the semicarbazone melted at 183-185°(lit.26 mp 186-187°).3,3-Dimethyl[3.2.1]bicyclooctanone-2 (7): bp 30-40°(0.3 mm); ir 1710, 3050, and 1610 cm-1 (the latter indicated olefinic contamination); vpc (200°)18 indicated three compounds present. The distillate, dissolved in petroleum ether (bp 30-60°), was placed upon a column containing 30 g of neutral alumina. Elution with petroleum ether yielded an unidentified olefin, ir 3050 and 1610 cm-1, no carbonyl or hydroxyl absorptions present.Elution with 50% (v/v) benzene-petroleum ether yielded 2 g of 7 (25) O.

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Magnetic susceptibilities have been measured in the temperature region 1.7–60°K both parallel and perpendicular to the chemical chain on single crystals of Cu(pyrazine)(NO3)2. It has been shown that there is qualitative disagreement between experiment and theory if the appropriate equations derived for the Ising model in one dimension are applied. On the other hand, excellent agreement exists for the Heisenberg model with J/k = −5.3°K down to the lowest temperature achieved, along with closer agreement between the g values determined in this experiment and those obtained by EPR. A comparison is also made between the exchange pathway in Cu(NO3)2 · 2.5H2O and the probable pathway in Cu(pyrazine)(NO3)2.