Formaldazine photodissociation and the pair formation of H sub 2 CN radicals

Journal Article · Wed Mar 06 23:00:00 EST 1991 · Journal of Physical Chemistry; (USA)

DOI:https://doi.org/10.1021/j100158a012· OSTI ID:5619366

Felder, P; Huber, J R ^[1]; Harrison, J A ^[2]

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1. Physikalisch-Chemisches Institut der Universitaet Zuerich (Switzerland)
2. Univ. of California, Berkeley (USA)

The dissociation of formaldazine, H{sub 2}CN-NCH{sub 2}, following excitation at 193 nm has been studied by molecular beam photofragment translational spectroscopy. The only primary process, H{sub 2}CN-NCH{sub 2} {yields} 2H{sub 2}CN, takes place within a rotational period ({approx}10{sup {minus}12} s) of the parent molecule and leads to the formation of H{sub 2}CN radical pairs. The low translational energy release of merely 22% of the available energy indicates predissociation and furthermore implies that most of the nascent radicals possess enough internal energy to overcome the barrier E{sup *} of the reaction H{sub 2}CN {yields} H + HCN. Based on the translational energy distribution P(E{sub T},H{sub 2}CN) and the threshold energy E{sup *} = 30 kcal/mol, it is estimated that for 66% of the H{sub 2}CN radical pairs both members decay and for 33% one partner is stable while the other one decays. Hence, after absorption of a photon approximately 80% of the H{sub 2}CN radicals undergo a secondary dissociation step to HCN and H atoms.

• OSTI ID: 5619366
• Journal Information: Journal of Physical Chemistry; (USA), Journal Name: Journal of Physical Chemistry; (USA) Vol. 95:5; ISSN 0022-3654; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
AZINES
BEAMS
CHEMICAL REACTIONS
DATA
DATA ANALYSIS
DISSOCIATION
EXPERIMENTAL DATA
HETEROCYCLIC COMPOUNDS
INFORMATION
MEASURING METHODS
MOLECULAR BEAMS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
RADICALS