Računalno istraživanje reakcija slobodnih radikala s halogeniranim organskim spojevima u vodenim otopinama

Nikšić-Franjić, Ivana (2020) Računalno istraživanje reakcija slobodnih radikala s halogeniranim organskim spojevima u vodenim otopinama. Doctoral thesis, Ruđer Bošković Institute.

Preview

PDF (Doctoral thesis) - other
Download (5MB) | Preview

Abstract

In this doctoral thesis the reaction mechanisms and kinetics of free radical reactions with halogenated organic compounds in non-buffered and buffered (bicarbonate and phosphate) aqueous solutions were investigated. This includes a study of the reactivity of C-centered α-aminoalkyl radicals: •CH(CH_3 ) NH_2, •CH(CH_3 ) NHCH_3, glycyl radical anion •CH(NH_2 ) COO^- and hydrogen atom (H^•) with haloacetates: chloro-, bromo- and iodoacetate and a halogenated nucleobase 5-bromouracil. Reactions exhibit a variety of fundamentally important competing mechanisms, of which the most important one is the proton coupled electron transfer. The solvent was initially described implicitly, and then the influence of explicit water molecules on the mechanisms and reaction energetics was explored. Based on the parameters calculated by the theory of density functional theory (DFT), the dominant reaction mechanisms and reaction kinetics were determined. The reaction rate constants were calculated employing the conventional and variational transition state theory with semiclassical corrections for the tunneling. By systematically climbing up the Jacob's ladders of DFT, for the set of radical reactions, we investigated which types of exchange-correlation functionals produce the rate constants in best agreement with the measured ones.

Item Type:

Thesis (Doctoral thesis)

Uncontrolled Keywords:

aqueous solutions; density functional theory; free radicals; halogenated organics; reaction kinetics; reaction mechanisms

Subjects:

NATURAL SCIENCES > Chemistry > Physical Chemistry

Divisions:

Division of Physical Chemistry

Projects: