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The stability of methyl p -hydroxybenzoate during 60 Co γ-radiolysis was studied in the solid state and in 10 μM water solution. The work was undertaken as a model to be extended to radiolytic sterilization of pharmaceutical preparations. Only in water moderate decomposition was observed at high doses (50 KGy, whilst at 5 kGy sterilization was verified. Methylparaben labelled with carbon-14 on the carboxyl group provided the decomposition yield by the reverse isotope dilution method; mass balances were drawn and mechanisms suggested.

Atrazine is completely destroyed when dissolved in water and moderately irradiated (doses 0.1–50 kGy) with 60 Co; the radiolytic products and their mass balances were determined.

The relevant peaks of the H2 chemical ionization mass spectra of C1C4 amines, thiols, alcohols and chloroalkanes are reported. The stability of alkylonium ions is discussed on the basis of the proton affinity of the starting neutrals, the substituent alkyl group, and the functional group. The main decomposition paths of [M+1]+ ions are described, and the formation of significant ions is discussed.

A complex of the macrocyclic aminopolyether Kryptofix® 2.2.2. and potassium carbonate was used to synthesize [18F]-CH2BrF from dibromomethane. At the no-carrier-added level the nucleophilic 18F-for-Br exchange gives rise to a corrected radiochemical yield up to 62%.

γ-Irradiation of solutions of (+)-tartaric acid and of meso-tartaric acid in tritiated water at pH 7 leads to an exchange of carbon-bonded hydrogen with the solvent. For each substrate the exchange proceeds to an approximately equal extent with inversion and with retention of configuration. The results support the conclusions of a similar stereochemical study on cis- and trans-cyclohexane-1,2-diols.

The decomposition of gaseous cyclopropyl-methylbromonium ions has yielded the cyclic hydro-carbons cyclopropane and methylcylclopropane, and methyl bromide.

The thermal gaseous cyclo-C3H5BrCH3+ ion, formed by the reaction of CH3ClCH3+ ion, but not of CH3FCH3+ ion, with cyclopropyl bromide, reacts with benzene as a methylating and as an allylating agent with equal facility. The loss of the cyclic structure results either from a concerted ring cleavage during the attack or from rearrangement of cyclopropylarenium ion after the attack. The methylating ability of cyclopropyl(methyl)bromonium ion toward benzene falls between those of dimethylfluoronium and dimethylchloronium ions, i.e. CH3FCH3+ > cyclo-C3H5-BrCH3+ > CH3ClCH3+.

The gase-phase reactions of 3HeT+, CX3+, and C6X5+(X = H or T), produced by β– decay, with cyclopropyl bromide were studied by analysis of the radioactive neutral products. Competition between the ring and the bromine atom as reaction sites was observed. A comparison with previous gas-phase and condensed-phase studies is given.

CX3+ ions (X = H, T), formed by the spontaneous β– decay of CX4, were allowed to react with gaseous CH3Y (Y = F, Cl, and Br) in the presence of a trace amount of toluene. The formation of radioactive isomeric xylenes, arising from the attack of CH3YCH3+ ion to C7H8, is discussed.