ChemInform Abstract: AN ESR INVESTIGATION OF THE COMPLEX FORMATION BETWEEN SULFUR DIOXIDE AND ELECTROGENERATED SULFUR DIOXIDE ANION RADICAL

1979 ◽  
Vol 10 (43) ◽  
Author(s):  
B. KASTENING ◽  
B. GOSTISA-MIHELCIC
Keyword(s):  
Sulfur Dioxide ◽  
Complex Formation ◽  
Anion Radical

Host–Guest interaction of pesticide bifenox with cyclodextrin molecules. An electrochemical study

2009 ◽  
Vol 74 (11-12) ◽  
pp. 1647-1664 ◽  
Author(s):  
Magdaléna Hromadová ◽  
Romana Sokolová ◽  
Lubomír Pospíšil ◽  
Štěpánka Lachmanová ◽  
Nicolangelo Fanelli ◽  
...  
Keyword(s):  
Complex Formation ◽  
Anion Radical ◽  
Formation Constants ◽  
Aprotic Solvents ◽  
Reduction Wave ◽  
Nitroaromatic Compound ◽  
Complex Formation Constants ◽  
Oh Groups ◽  
Stable Anion ◽  
Main Factor

The reduction of nitroaromatic compound bifenox (methyl 5-(2,4-dichlorophenoxy)-2-nitrobenzoate) was studied in aprotic solvents in the absence or presence of cyclodextrin (CD) molecules of different cavity sizes. βCD and γCD form complexes with bifenox in DMSO with the complex formation constants (5 ± 2) × 102 M–1 [βCD–bifenox] and (3 ± 1) × 102 M–1 [γCD–bifenox], respectively. Bifenox yields a relatively stable anion radical in dimethyl sulfoxide, which is further reduced at more negative potentials by an overall addition of three electrons and four protons to the corresponding phenylhydroxylamine. In the presence of βCD the first reduction wave of bifenox becomes irreversible, it is shifted towards more positive potentials and the uptake of more than one electron is observed (up to four electrons during the exhaustive electrolysis). The first reduction wave of bifenox is not affected by the addition of glucose confirming that a simple availability of protons from the OH groups is not the main factor in further transformation of anion radical in the presence of βCD. The complex formation with βCD facilitates the protonation and additionally protects the molecule from disintegration into 2,4-dichlorophenol. A yield of 2,4-dichlorophenol decreases in the order βCD, γCD and αCD, respectively.

Interaction of sulfur dioxide with heteropolyanions in nonpolar solvents. Evidence for complex formation

1987 ◽  
Vol 26 (1) ◽  
pp. 215-216 ◽  
Author(s):  
Dimitris E. Katsoulis ◽  
Valerie S. Tausch ◽  
Michael T. Pope
Keyword(s):  
Sulfur Dioxide ◽  
Complex Formation ◽  
Nonpolar Solvents

scholarly journals The Mechanisms of the Dimerization of Sulfur Dioxide Anion Radical in the Presence of Tetraalkylammonium Ions in DMF.

1983 ◽  
Vol 37a ◽  
pp. 423-430 ◽  
Author(s):  
Vernon D. Parker ◽  
Francesco Salvatore ◽  
T. Østvold ◽  
Harald Høiland ◽  
D. L. Powell ◽  
...  
Keyword(s):  
Sulfur Dioxide ◽  
Anion Radical ◽  
Tetraalkylammonium Ions

Complex formation between sulfur dioxide and halide ions

1977 ◽  
Vol 55 (15) ◽  
pp. 2807-2812 ◽  
Author(s):  
Etela Milanova ◽  
Robert L. Benoit
Keyword(s):  
Sulfur Dioxide ◽  
Complex Formation ◽  
Enthalpy Of Solution ◽  
Halide Ions ◽  
Iodide Ions ◽  
Enthalpy Changes ◽  
Stability Order ◽  
The Difference ◽  
The Stability ◽  
Dipolar Aprotic Solvents

Complex formation between sulfur dioxide and iodide ions in acetonitrile (AN) has been studied by vapour pressure measurements. The enthalpy changes ΔH0 for 1:1 association reactions between SO2 and halide (X−) ions in AN and between SO2 and Cl− in dimethylsulfoxide (DMSO) have been determined at 25 °C by calorimetry. The ΔH0 values (kcal mol−1) are respectively −4.1 (Cl−), −3.4 (Br−), −3.0 (I−) in AN and −0.7 (Cl−) in DMSO. In contrast to previous literature data there is a linear relationship between these ΔH0 and reported ΔG0 values for the formation of the SO2X− complexes in AN. The difference between the ΔH0 values for SO2Cl− in the solvents AN and DMSO is accounted for by the more exothermic enthalpy of solution of SO2 in DMSO which is the more basic solvent, and by the expected minor difference in the enthalpies of transfer of Cl− and SO2Cl− from AN to DMSO, both dipolar aprotic solvents. Some of the problems connected with the stability order of the SO2X− complexes are discussed in relation to solvent effects and properties of X−.

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