Chemical reactions of organic molecules adsorbed on ice 1. Chlorine addition to propene
Chemical reactions that are promoted or catalyzed by the surface or near surface regions of ice particles in type II polar stratospheric clouds (PSCs) have been shown to play a role in the annual sequence of events that ultimately opens the Antarctic ozone hole. A new ice-catalyzed chemical reaction is reported, namely the addition of Cl{sub 2} to the C--C double bond of propene (C{sub 3}H{sub 6}) to form 1,2-dichloropropane. The reaction, which was investigated with temperature-programmed desorption mass spectrometry (TPD), was carried out on ultrathin (10--100 monolayer thick) films of ice deposited on single-crystal metal substrates under ultrahigh vacuum. The Cl{sub 2}-addition product was identified as 1,2-dichloropropane on the basis of its fragmentation pattern in the mass spectrometer. 1,2-Dichloropropane formation occurs below 150 K, and no chlorohydrin (e.g., 2-chloro-1-propanol) evolution is ever observed. The reaction of coadsorbed propene and chlorine is very different from what occurs in aqueous solutions, where chlorohydrin formation occurs readily. Possible mechanisms of the ice-surface-catalyzed reaction are discussed.
- Research Organization:
- Univ. of Minnesota, Minneapolis, MN (US)
- OSTI ID:
- 20017305
- Journal Information:
- Journal of Physical Chemistry B: Materials, Surfaces, Interfaces, amp Biophysical, Vol. 104, Issue 5; Other Information: PBD: 10 Feb 2000; ISSN 1089-5647
- Country of Publication:
- United States
- Language:
- English
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