The activity and stability of tertiary amine catalysts in the presence of hypochlorous acid

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dc.contributor Aalto-yliopisto fi
dc.contributor Aalto University en
dc.contributor.advisor Perrin, Jordan Dawson, Owain 2018-09-03T12:41:54Z 2018-09-03T12:41:54Z 2018-08-28
dc.description.abstract Hypochlorous acid is an electrophilic oxidizing agent capable of reacting with a range of unsaturated organic substrates. Previously, these reactions have been shown to be catalysed by the use of a tertiary amine, and Hcat hardwood pulp bleaching stages using the tertiary amine DABCO, as well as its derivative CM-DABCO, have proved efficient. Within this work, a range of DABCO-derivative structures were synthesised, and their catalytic abilities and stabilities were tested via the use of stopped-flow UV-Vis spectroscopy. DABCO-derivatives produced in this work all involved mono-N-substitution, and generally high yields could be achieved in simple synthetic routes. Derivative structures tested included allyl (AL), carboxymethyl (CM), carboethoxymethyl (CEM), carbamoylmethyl (AA) and 2-hydroxyethyl (EA) groups. The pKa of the tertiary amine group within these were measured, and found to each be between 3.0 and 3.4, close to the second pKa of DABCO itself (2.97). Both pH and substrate structure were found to have a significant impact on the catalytic ability of all the tested structures. Due to the chlorinating action of Cl2 at pH 3, and the large difference between pH and DABCO-derivative catalyst pKa at pH 7, generally low catalytic factors were found at these pH values. At pH 5, higher catalytic factors could be found, with a catalyst pKa closer to 5 producing an increased catalytic ability. The substrate structure affects the rates of catalysis but not the order of activities between the different catalysts. CM-DABCO was the most active derivative for all substrates at pH 5, and it was concluded that further increases to the catalyst pKa could further improve the results obtained. Unlike DABCO, all the synthesised derivatives were shown to be close to fully stable for up to 10 seconds of pre-incubation with hypochlorous acid. Stability is concluded then to not be a concern in the selection and design of an optimal DABCO-derivative catalyst structure. en
dc.format.extent 63 + 13
dc.format.mimetype application/pdf en
dc.language.iso en en
dc.title The activity and stability of tertiary amine catalysts in the presence of hypochlorous acid en
dc.type G2 Pro gradu, diplomityö fi Kemian tekniikan korkeakoulu fi
dc.subject.keyword tertiary amine en
dc.subject.keyword catalysis en
dc.subject.keyword hypochlorous acid en
dc.subject.keyword DABCO en
dc.subject.keyword stopped-flow en
dc.subject.keyword UV-Vis spectroscopy en
dc.identifier.urn URN:NBN:fi:aalto-201809034878
dc.programme.major Biomass Refining fi
dc.programme.mcode CHEM3021 fi
dc.type.ontasot Master's thesis en
dc.type.ontasot Diplomityö fi
dc.contributor.supervisor Vuorinen, Tapani
dc.programme Master's Programme in Chemical, Biochemical and Materials Engineering fi
dc.location PK fi
local.aalto.electroniconly yes
local.aalto.openaccess yes

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