Pulse Radiolysis of Neopentane in the Gas Phase.

The pulse radiolysis of gaseous neopentane has been investigated in the absence and presence of electron scavengers (SF, CDI, CCl). Deuterium labeling experiments show that the stable product molecules can be accounted for by (a) radical combination reactions involving mainly CH and H; (b) hydride ion transfer reactions involving CH , CH , and CH ; (c) neutralization reactions of CH and CH ; and (d) unimolecular dissociation of the parent ion (CH ) and of electronically excited neopentane. Neutralization of the -CH ion, which is the major positive ion in the system occurs as follows: (a) -CH + e → -CH + H and (b) -CH + → 2CH + CH. It is shown that CH produced in hydride ion transfer reaction C H + neo-CH → C H + CH (where C H = CH , CH , and CH ) rearranges to the CHC(CH)CHCH structure prior to neutralization. A detailed accounting of all products produced in the unimolecular and bimolecular reactions led to the conclusion that the ratio of neutral electronically excited molecules to parent ions (N/N) is 0.28.