Naslov
Why Hypochlorous Acid Chlorinates Amines Rather than Hydroxylates Them

Autori
Šakić, Davor ; Tandarić, Tana ; Vrček, Valerije

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
15th European Symposium of Organic Reactivity, Book of Abstracts / Reiner Harges - Kiehl, 2015, 165-165

Skup
15th European Symposium of Organic Reactivity

Mjesto i datum
Kiel, Njemačka, 31.08.2015. - 04.09.2015

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
amine ; hocl ; mechanism

Sažetak
Reactions of hypochlorous acid (HOCl) with ammonia, (di)methylamine, and heterocyclic amines have been studied computationally in the gas phase and aqueous medium. Different oxidation pathways are possible in the gas phase, and only one is experimentally detected in aqueous solution. N-chlorination pathway is prohibitively expensive in the gas phase (deltaGcalc > 250 kJ/mol), yet N-chloramines are readily detected in aqueous medium. N- hydroxylation is more feasible process in the gas phase, while in aqueous medium is much less preferred. We have found that the explicit solvent effects are crucial for determination of reaction mechanism in aqueous medium. Water molecules play important catalytic role in N- chlorination reaction, by facilitating the hydrogen-atom transfer between amines and HOCl. The planar structural motif, which includes HOCl, amine and two reactive water molecules, has been calculated as the most stable configuration for up to 9 explicit water molecules. In case of N-hydroxylation reaction, water molecules are not directly involved in the O-transfer process. The linear structural motif has been found as the most preferable configuration, in which all water molecules contribute in building the first hydration shell, and participate as reaction spectators only. Catalytic effect of explicit water molecules, observed for N-chlorination of amines, has not been calculated for N- hydroxylation process.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

POVEZANOST RADA