Kinetics, thermodynamics, and mechanism of the formation of benzaldehyde-sulfur(IV) adducts

Olson, Terese M.; Boyce, Scott D.; Hoffmann, Michael R.

doi:10.1021/j100402a043

Cited by 15 publications

(25 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The value of the entropy of activation is more negative than we might generally expect for addition reactions of monopositive and mononegative ions. Similar values have been obtained for the addition of bisulfite to formaldehyde (AS*= -108.0 J K-I mol-I (33)), benzaldehyde (AS*= -142.35 J K-I mol-I), and other related compounds (32), and for methylglyoxal (AS* = -77.7 J K-' mol-' (36)). Bunting and Meathre1 (6) obtained AS* = -71.0 J K-' mol-I for the reaction between 10-methylacridinium cation and OH-.…”

Section: Mechanism and Kinetic Analysissupporting

confidence: 74%

“…Bunting and Meathre1 (6) obtained AS* = -71.0 J K-' mol-I for the reaction between 10-methylacridinium cation and OH-. Olson et al (32) have proposed that the transition complex for the addition of bisulfite to benzaldehyde is a cyclic structure formed between the carbonyl and bisulfite groups. In our case it is difficult to establish a possible structure for the transition complex, which would have a high charge separation that would contribute to the low value of AS*.…”

Section: Mechanism and Kinetic Analysismentioning

confidence: 99%

See 1 more Smart Citation

Kinetics and mechanism of covalent addition of S(IV) species to the acridinium cation

Ros¹,

Thomas²,

Crovetto³

et al. 1996

Can. J. Chem.

View full text Add to dashboard Cite

Abstract:The reaction of acridine with S(1V) species (SO,.H,O, HSO;, and SO,' -) to form the adduct acridine-S (IV) has been studied spectrophotometrically throughout the pH range 2.6-8 in aqueous solutions. The observed pseudo-first-order rate constants, k,,,, were determined at 25°C and ionic strength I = 0.11 M, and the pH profile of the rate reached a maximum at pH = 6.1. At constant pH the kobs values were a linear function of the total S(1V) concentration with slopes that increased significantly with pH. These data are consistent with the rate-determining attack of S0,H-and SO,' -upon the C-9 of the acridinium cation. A nonlinear least-squares fitting of the experimental values to the model equation, within the overall pH region studied, yields the pH-independent rate constants k, = 3.7 2 0.1 and k, = (6.24 C 0.04) x lo4 M-' s-' for the attack of these two species, respectively. The experimental results agree very well with the kinetic model. Due to the experimental conditions used we did not detect any possible pseudobase formation in the pH range studied. The reactivity of the S(IV) species with acridine follows the order: SO: ->> HSO; >> S02,H,0. The value obtained for the ratio k,lk, is similar to the results given for other addition reactions of S(1V) species to the double bond of carbonyl compounds such as benzaldehyde and formaldehyde.Key words: covalent addition, acridine, acridine -S(1V) adducts, kinetics and mechanism.RCsumC : L'acridine rCagit avec le S(1V) sous la forme de SO,.HZO, HS0,-et ~0 , ' -~o u r conduire j. des adduits que l'on a CtudiC d'une faqon spectrophotomCtrique j. tous les pH allant de 2,6 j. 8, en solutions aqueuses. On a dtterminC les constantes de vitesse du pseudopremier ordre, kobs, j. 25°C et j. une force ionique I = 0,I I M; les profiles des vitesses en fonction du pH atteignent un maximum j. pH = 6,l. A des pH constants, les valeurs de k,,, sont des fonctions lineaires de la concentration totale en S(1V) avec des pentes qui augmentent d'une f a~o n importante avec le pH. Ces donnees sont en accord avec une attaque qui dtterminerait la vitesse de la reaction du HS0,-et du SO:-en position C-9 du cation acridinium. Un ajustement non linCaire par la mCthode des moindres carrCs des valeurs experimentales obtenues dans la region globale de pH CtudiCs avec 1'Cquation modkle permet de tirer des constantes de vitesses independantes du pH, k, = 3,7 t 0,l et k? = (6,24 2 0.04) x 10' M-' s-I pour les attaques respectives de ces deux espkces. Les resultats experimentaux sont en bon accord avec le modkle cinktique. A cause des conditions experimentales utilisees, on n'a pas pu dCtecter la formation de pseudobases dans la plage de pH CtudiCs. La rCactivit6 des espkces S(1V) avec I'acridine est dans l'ordre suivant : SO,' ->> HSO; >> SO,.H,O. La valeur obtenue pour le rapport k,lk, est semblable j. celle tiree de resultats rapportes pour d'autres reactions d'addition d'espkces S(1V) 21 des doubles liaisons de composts carbonyles, tels que le benzaldkhyde et le formaldehyde.

show abstract

Section: Mechanism and Kinetic Analysissupporting

confidence: 74%

Section: Mechanism and Kinetic Analysismentioning

confidence: 99%

Kinetics and mechanism of covalent addition of S(IV) species to the acridinium cation

Ros¹,

Thomas²,

Crovetto³

et al. 1996

Can. J. Chem.

View full text Add to dashboard Cite

show abstract

“…The rate coefficients for the right and left direction were set to k E1 = 2.2 × 10 3 s –1 and k –E1 = 1.0 × 10 10 m –1 s –1 as K a2 = 2.2 × 10 –7 m –1 for sulfur(IV) in the thiosulfatolysis and sulfitolysis of pentathionate in the present work. Here, K a2 approaches the value for the sulfite equilibrium proposed by Hoffmann, for which the corrected acidity constant c K a2 = 2.43 × 10 –7 m for an ionic strength of 0.5 m . The ionic strength of our buffer solution was 0.075 m ; thus, for the protonation process of sulfite in our present work, we set K a2 = 2.2 × 10 –7 m –1 , which is also approximately the same value as that used in our recent work …”

Section: Discussionmentioning

confidence: 61%

The Key Heterolysis Selectivity of Divalent Sulfur–Sulfur Bonds for a Unified Mechanistic Scheme in the Thiosulfatolysis and Sulfitolysis of the Pentathionate Ion

et al. 2016

View full text Add to dashboard Cite

The thiosulfatolysis and sulfitolysis of pentathionate were studied in the pH ranges 4.50-8.0 and 4.0-5.0 at T = (25.0 ± 0.1)°C by HPLC monitoring of the time-dependence and distribution of different sulfur species. The two systems are first order with respect to both reactants. In contrast to tetrathionate, pentathionate and higher polythionates contain inequivalent divalent sulfur atoms; therefore, the complexity of the mechanism increases. The selective heterolytic cleavages of [a]

show abstract

“…This erroneous value for k 4r was taken from Betterton and Hoffmann, 7 which in turn obtained it from Stewart and Donnally, 8 while we use a value that is derived from K 4 and k 4f . Our value for k 4f is from Olson et al 1 The equilibrium constant for reaction 5 is from Betterton et al 6 This paper discusses the values for this equilibrium constant reported previously, and in particular it points out the erroneous value in Stewart and Donnally. 8 The forward and reverse rate constants are assigned to give this equilibrium constant and a diffusion-controlled value for k 5r .…”

mentioning

confidence: 74%

“…The equilibrium constant and forward rate constant for reaction 1 come from Olson et al, although there are several similar prior reports of these values. 1 The value of K 2 is at µ = 0.1 M as recommended in the NIST database. 2 The forward rate constant for reaction 3 is from the pulse radiolysis study of Merényi et al 3 However, the actual value they reported was 2.6 × 10 6 M -1 s -1 .…”

mentioning

confidence: 99%

Kinetics of the Benzaldehyde-Inhibited Oxidation of Sulfite by Chlorine Dioxide

2015

View full text Add to dashboard Cite

There has been steady interest in the aqueous reaction of ClO2• with sulfur(IV) since the 1950s, and a wide variety of rate laws and mechanisms have been proposed. In neutral-to-alkaline media, the reaction is challenging to study because of its great rate. Here it is shown that benzaldehyde can be used as an additive to slow the reaction and make its rates more amenable to study. The rates can be quantitatively modeled by a mechanism that includes reversible binding of sulfur(IV) by benzaldehyde and a rate-limiting mixed second-order reaction of ClO2• with SO3(2-). The latter reaction occurs through parallel electron transfer from SO3(2-) to ClO2• and oxygen-atom transfer from ClO2• to SO3(2-).

show abstract

Kinetics, thermodynamics, and mechanism of the formation of benzaldehyde-sulfur(IV) adducts

Cited by 15 publications

References 0 publications

Kinetics and mechanism of covalent addition of S(IV) species to the acridinium cation

Kinetics and mechanism of covalent addition of S(IV) species to the acridinium cation

The Key Heterolysis Selectivity of Divalent Sulfur–Sulfur Bonds for a Unified Mechanistic Scheme in the Thiosulfatolysis and Sulfitolysis of the Pentathionate Ion

Kinetics of the Benzaldehyde-Inhibited Oxidation of Sulfite by Chlorine Dioxide

Contact Info

Product

Resources

About