Sökning: onr:"swepub:oai:DiVA.org:su-26801" >
An improved method ...
An improved method for assessing relative nucleophilic substitution reactivities of polychlorinated benzenes
-
Qiu, Yanling (författare)
-
- Eriksson, Johan (författare)
- Stockholms universitet,Institutionen för miljökemi,Percistency
-
- Granelli, Lisa (författare)
- Stockholms universitet,Institutionen för miljökemi,Percistency
-
visa fler...
-
- Bergman, Åke (författare)
- Stockholms universitet,Institutionen för miljökemi
-
visa färre...
-
(creator_code:org_t)
- Elsevier BV, 2009
- 2009
- Engelska.
-
Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 75:1, s. 78-82
- Relaterad länk:
-
https://urn.kb.se/re...
-
visa fler...
-
https://doi.org/10.1...
-
visa färre...
Abstract
Ämnesord
Stäng
- An existing substitution reaction method was improved as part of a system to measure the persistency of selected chemicals in the environment by evaluating their chemical reactivity. Hexachlorobenzene (HCB), pentachlorobenzene, 1,2,4,5-tetrachlorobenzene and 1,2,4-trichlorobenzene were selected as model compounds. Sodium methoxide in methanol was used as a nucleophile and found to be stable for at least 35 days after preparation. The substitution reaction system was modified so that nitrogen protection was not necessary to avoid oxidation and hydrolysis effects, which led to improved results. The reactivity of polychlorinated benzenes (PCBz), which substituted chlorine for methoxide according to a second-order rate constant, increased as the number of chlorine atoms on the benzene ring increased. HCB was selected as a standard for the k2 calculations of the substitution reactions. A normalized k2 (kN) was calculated as kN = kPCBz/kHCB. GC–MS analysis confirmed that the reactions were pure nucleophilic aromatic substitutions without side reactions.
Ämnesord
- NATURVETENSKAP -- Geovetenskap och miljövetenskap -- Miljövetenskap (hsv//swe)
- NATURAL SCIENCES -- Earth and Related Environmental Sciences -- Environmental Sciences (hsv//eng)
Nyckelord
- Nucleophilic substitution
- Polychlorinated benzenes
- Nucleophile
- Reactivity
- Persistency
- Chemical stability
- Environmental chemistry
- Miljökemi
Publikations- och innehållstyp
- ref (ämneskategori)
- art (ämneskategori)
Hitta via bibliotek
Till lärosätets databas