The Interaction of Sulfite Ion with 2,4,6-Trinitrobenzaldehyde: Kinetic, Equilibrium, and Proton Magnetic Resonance Studies

Abstract

Sulfite ion reacts with 2,4,6-trinitrobenzaldehyde in aqueous solution of ionic strength 0.14 M to yield a 1 :1 o-con~plex at low sulfite concentrations and a 2: 1 o-complex at high sulfite concentrations. The visible absorption characteristics of these two o-complexes as well as equilibrium constants and relevant thermodynamic parameters for their formation have been determined. P.n~.r. studies demonstrate that two isomeric forms of the 1 : 1 o-complex occur in aqueous dimethylsulfoxide solution and two isomeric forms of the 2 : l o-complex occur in water. Iri both the 1 :1 and the 2 : l complexes isomers are found which contain sulfite ion attached to the C-1 carbon and one of the isomeric 2 : 1 o-complexes is postulated to exist in cis and trans forms. Observations are presented concerning the kinetics of the very rapid formation of the 1 :1 o-complex in water.L'ion si~lfite reagit avec la trinitro-2,4,6 benzaldehyde en solution aqileilse de force ioniqi~e 0.14 M pour donner iln complexe I : 1 a des concentrations faibles de si~lfite et iln coniplexe 2: 1 i des concentrations Clevees de sulfite. On a determine les caracteristiqi~es d'absorption de ces deux complexes ainsi qile les constantes d'kquilibres et les parametres thermodynaniiques-se rapportant a leur formation. Des etudes en r.m.p. ont montrt que deux fornies isomeriques du complexe 1 : 1 se forment en solution aqueuse de sulfoxyde de dimethyle et que deux fornies isomeriques du complexe 2:l se forment dans I'eai~. On a trouvk dans les deux coniplexes I : 1 et 2: 1 des isomtres qui contiennent l'ion sulfite relie ail carbone C-I. De meme on admet que I'un des con~plexes 2: 1 isomeriques existe sous des formes cis et trans. On prksente aussi des observations se rattachant a la cinetique de formation tres rapide du complexe 1 :

Potential for Abiotic Reduction of Pesticides in Prairie Pothole Porewaters

“…According to the standard reduction potentials of relevant sulfur redox couples (e.g., HS – , S n 2– , SO 3 2– , and S 2 O 3 2– ; see Table S5, Supporting Information), it appears that SO 3 2– and S 2 O 3 2– are thermodynamically capable of reducing dinitroanilines. Previous studies, however, have shown that SO 3 2– and S 2 O 3 2– may only act as nucleophiles and undergo rapid reversible formation of anionic Meisenheimer complexes with NACs including dinitroanilines. − Such reversible reactions, however, did not seem to compete with the reductive transformation promoted by HS – and S n 2– .…”

Kinetic and equilibrium studies of ?-adduct formation and substitution in the reactions of sulphite ions with some alkyl and aryl ethers and thioethers

“…[3][4][5][6][7][8] Reports of attack at substituted ring positions leading to nucleophilic displacement are relatively scarce, although it is known that substitution of halide ions leads to the formation of derivatives of benzene sulphonic acid, 9,10 and there is one early report of the formation of an adduct by attack at the 1-position of 2,4,6-trinitrobenzaldehyde. 11 Here we compare the reactions with sulphite of the ethyl and phenyl ethers of 2,4,6-trinitrophenol and 2,4,6-trinitrothiophenol. It is known 12,13 that phenoxide and thiophenoxide are considerably better leaving groups than their aliphatic analogues, ethoxide and thioethoxide respectively.…”