Kinetika dimerizacije C-nitrozo spojeva u čvrstom stanju

doctoral thesis

• Title (english): Kinetics of dimerization of C- nitroso compounds in solid state
• Author: Katarina Varga
• Mentor: Hrvoj Vančik (mentor)
• Committee member: Vladislav Tomišić (predsjednik povjerenstva)
• Committee member: Hrvoj Vančik (član povjerenstva)
• Committee member: Davor Margetić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Chemistry); Zagreb
• Defense date and country: 2015-06-08, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry
• Universal decimal classification (UDC): 54 - Chemistry. Crystallography. Mineralogy

Abstract

Kao prikladan model za proučavanje kinetike i mehanizama reakcija organskih molekula u kristalima odabrana je jednostavna reakcija dimerizacije C-nitrozo spojeva. Kako defekti nastali sublimacijom i uređenost molekula u kristalnoj rešetci utječe na konstantu brzine dimerizacije 4-brom (1) i 4-jodnitrozobenzena (4) istraženo je u različitim topokemijskim okolinama: od molekula monomera koji se nalaze u rešetci dimera nakon fotolize, molekula monomera u vlastitoj kristalnoj rešetci do nasumično orijentiranih molekula monomera u tankom sloju. Iz temperaturne ovisnosti konstante brzine reakcije procijenjena je energija aktivacije za dimerizaciju 1 u čvrstom stanju. Iako se danas vrlo malo pažnje posvećuje proučavanju mehanizama termalno potpomognutih reakcija izomerizacije u čvrstom stanju, a mnogo fotokemijskim reakcijama, u ovom radu detaljno je istražena termalno potpomognuta izomerizacija E-3-halogennitrozobenzena u Z-dimerne analoge. Pošto direktna „unimolekularna“ E-Z izomerizacija do sada još nije opažena, pokazano je da se Z-E izomerizacija azodioksida u čvrstom stanju može odvijati bez stvaranja slobodnih nitrozo molekula. Praćena je kinetika dimerizacije u različitim topokemijskim okolinama, kao i izomerizacija E-3-klor (2) i E-3-bromnitrozobenzena (3) u Z-dimerne analoge pri različitim temperaturama, na temelju kojih su određeni odgovarajući parametri aktivacije za dimerizaciju i izomerizaciju u čvrstom stanju.

Abstract (english)

Dimerization of nitroso compounds has been used as a suitable model for kinetic studies of organic reactions in crystals. The influence of the surface defects caused by sublimation of molecules on the dimerization rates of 4-bromo (1) and 4-iodonitrosobenzene (4) has been investigated in various topochemical environments: from monomer molecules in the crystal lattice prepared by photolysis to the randomly oriented monomer molecules in a thin layer. The activation energy for the dimerization of 1 has been estimated from the temperature dependence of the reaction rate. Most of the literature on the isomerisation in the solid state is focused on the photochemical reactions and very little attention is paid to the thermally induced reactions. In this work we have been investigated the solid state thermal isomerization of the E-3-halogenonitrosobenzenes in their Z-dimeric analogues. It has been shown that azodioxide Z-E isomerization in the solid state could occur without the formation of the free nitroso molecules. Such „unimolecular” isomerization has not yet been observed. The reaction has been studied by measuring the reaction rate of dimerization in different topochemical conditions by exploring the isomerization of E-3-chloro (2) and E-3-bromonitrosobenzene (3) at different temperatures and also by analyzing activation parameters for the solid state dimerization and isomerization.

• Keywords: čvrsto stanje; dimerizacija; E-Z izomerizacija u čvrstom stanju; halogennitrozobenzen; kinetika; sublimacija; topokemija
• Keywords (english): dimerization; E-Z isomerization in the solid state; halogenonitrosobenzene; kinetics; solid state; sublimation; topochemistry
• Language: croatian
• URN:NBN: urn:nbn:hr:217:325405
• Study programme: Title: Doctoral study in chemistry; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti, područje prirodnih znanosti, polje kemija (doktor/doktorica znanosti, područje prirodnih znanosti, polje kemija)
• Type of resource: Text
• Extent: 139 str. ; 30 cm
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2018-08-31 08:51:52