In the present communication we have measured ionization energies (ZE) for molecular ions M+' as well as appearance energies ( A E ) for [M-l]+ fragment ions at threshold produced from benzyl alcohol, benzyl amine and benzyl cyanide. The electron impact, ZE and A E data were obtained by using an Atlas CH-4 mass spectrometer and the data were treated using the deconvoluted first differential (DFD) technique.' Metastable peaks associated with the formation of [M -1]+ fragment ions were recorded-using an MM 16F mass spectrometer-at low electron energy (9-12 eV) in order to avoid interference from normal fragment ions. Kinetic energy release values ( were calculated2 from metastable peak width at half height. Molecular Ions. ZE and A E [M -1]+ values are presented in Table 1 together with K E released and AH, values calculated for [M -1]+ ions.
Especially synthesized compounds, together with conventional antioxi‐dants, were evaluated as radiation stabilizers of isotactic polypropylene. Electron spin resonance (ESR) determinations of free radical populations in stabilized and unstabilized samples were carried out after irradiation and at periods of up to 460 h. The same samples were mechanically tested and a correlation was found to exist between the concentration of trapped peroxy radicals and the radiation deterioration in the polymer. Post‐irradiation effects were evaluated using accelerated aging at 70°C and carbonyl index determinations at periods of up to 110 days indicated that some of the stabilizers examined are efficient inhibitors of post‐irradiation oxidation. The results are discussed in the light of the free radical mechanism of the radiation‐induced auto‐oxidative degradation of polymers.
Alkylation of 5‐cyano‐4‐oxo‐6‐phenyl‐2‐thioxo‐1,2,3,4‐tetrahydropyrimidine I with methyl iodide, chloroacetic acid or 3‐chloro‐2,4‐pentanedione, afforded the S‐alkyl derivatives IIa‐c. 2‐Carboxymethylthio and 2‐(2′,4′‐dioxopentan‐3‐ylthio) derivatives IIb and IIc could be cyclised by acetic anhydride or polyphosphoric acid to give 6‐cyano‐3,5‐dioxo‐5H‐7‐phenylthiazolo[3,2‐a]pyrimidine III and 2‐acetyl‐6‐carboxamido‐5H‐3‐methyl‐7‐phenylthiazolo[3,2‐a]pyrimidine‐5‐one IX, respectively. Benzoylation of 2‐hydrazinopyrimidine derivative XII, in anhydrous dioxan, afforded the N‐benzoyl derivative XIII, which could be cyclised by heating in dimethylformamide to give 5‐amino‐6‐cyano‐3,7‐diphenyl‐s‐triazolo[4,3‐a]pyrimidine (XIV). The 2‐hydrazinopyrimidine derivatives XII and XV reacted with benzoyl isothiocyanate in dioxane to yield 4‐benzoylthiosemicarbazide derivatives XVI and XVII, which were converted into the 2‐s‐trizolopyrimidine derivatives XVIII and XIX, respectively. Also, XVI and XVII reacted with 2,4‐pentanedione and 3‐chloro‐2,4‐pentanedione to yield 2‐pyrazolopyrimidine derivatives XX and XXI, respectively.
The electron ionization mass spectra of 2-and 4-chlorodiphenylamine and 2-and 4-bromodiphenylamine are reported. All the spectra are characterized by strong molecular ion signals, corresponding to the base peak. Two primary fragmentations of significance include the expulsion of the substituents X and HX (X = halogen) from the four compounds. Further dissociation of the primary fragment ions results in the formation of some secondary decomposition ions having low or negligible relative abundances.
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