General and theoretical aspects of the peroxide group

Cremer, Dieter

doi:10.1002/9780470771730.ch1

Cited by 11 publications

(5 citation statements)

References 283 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Also, a decrease of the O-O bond strength by ca. 10 kcal/mol is well in line with the known fact that O-O bonds get weaker upon replacing H in hydroperoxides by alkyl or acyl groups (46).…”

Section: Resultssupporting

confidence: 83%

Thermodynamics of Peroxynitrite and Its CO₂ Adduct

Merényi

Lind

1997

Chem. Res. Toxicol.

102

View full text Add to dashboard Cite

The equilibrium constant, K3, of aqueous homolysis of peroxynitrous acid into hydroxyl and nitrogen dioxide free radicals was estimated to be 5 x 10(-10) M. This value was derived from a thermodynamic cycle by use of the experimentally known delta fH degree(ONOO-,aq) = -10.8 kcal/mol and the enthalpy of ionic dissociation of ONOOH(aq), delta H degree 1 = 0 kcal/mol, as well as of the entropy of gaseous ONOOH, S degree(ONOOH,g) = 72 eu. Furthermore we assumed the entropy of hydration of ONOOH, delta S degree 2, to be -25 eu, a value closely bracketed by the hydration entropies of analogous substances. The rate constant of radical recombination of OH. with NO2. to yield ONOOH, k-3, was resimulated from experimental data and found to be ca. 5 x 10(9) M-1 s-1. Together with the estimated K3, this yields the homolysis rate constant k3 = 2.5 s-1. This value is close to 0.5 s-1, the rate constant of formation of a reactive intermediate during the isomerization of peroxynitrous acid to nitrate. Our thermodynamic estimate is therefore consistent with substantial amounts of OH. and NO2. free radicals being formed in this process. The thermodynamic implications for the carbon dioxide/peroxynitrite system are also discussed.

show abstract

“…Also, a decrease of the O-O bond strength by ca. 10 kcal/mol is well in line with the known fact that O-O bonds get weaker upon replacing H in hydroperoxides by alkyl or acyl groups (46).…”

Section: Resultssupporting

confidence: 83%

Thermodynamics of Peroxynitrite and Its CO₂ Adduct

Merényi

Lind

1997

Chem. Res. Toxicol.

102

View full text Add to dashboard Cite

show abstract

“…Indeed, similar values were found experimentally in aqueous solutions for CH 3 C(OH)OONO and (CH 3 ) 2 C(OH)OONO . The dramatic decrease in the bond strength of O−O upon replacing H by an alkyl group has been noted before for both hydroperoxides and peroxynitrites . This effect has been attributed to the hyperconjugative stabilization of the alkoxyl radical as opposed to that of the unstabilized • OH radical.…”

Section: Discussionsupporting

confidence: 83%

Reaction of Organic Peroxyl Radicals with^•NO₂and^•NO in Aqueous Solution: Intermediacy of Organic Peroxynitrate and Peroxynitrite Species

2004

View full text Add to dashboard Cite

In this work, we studied the reactions of alkyl peroxyl radicals with • NO 2 and • NO using the pulse radiolysis technique. The rate constants for the reaction of • NO 2 with (CH 3 ) 2 C(OH)CH 2 OO • , CH 3 OO • , and c-C 5 H 9 OO • vary between 7 × 10 8 and 1.5 × 10 9 M -1 s -1 . The reaction produces relatively long-lived alkyl peroxynitrates, which are in equilibrium with the parent radicals and have no appreciable absorption above 270 nm. It is also shown that • NO adds rapidly to (CH 3 ) 2 C(OH)CH 2 OO • and CH 3 OO • to form alkyl peroxynitrites. The rate constants for these reactions were determined to be 2.8 × 10 9 and 3.5 × 10 9 M -1 s -1 , respectively. However, in contrast to alkyl peroxynitrates, alkyl peroxynitrites do not accumulate. Rather, they decompose rapidly via homolysis along the relatively weak O-O bond, initially forming a geminate pair. Most of this pair collapses in the cage to form an alkyl nitrate, RONO 2 , and about 14% diffuses out as free alkoxyl and • NO 2 radicals. A thermokinetic analysis predicts the half-life of CH 3 OONO in water to be less than 1 µs, an estimate that agrees well with previous experimental findings of ours for other alkyl peroxynitrites. A comparison of aqueous and gaseous thermochemistry of alkyl peroxynitrates reveals that alkyl peroxyl radicals and the corresponding alkyl peroxynitrates are similarly solvated by water.

show abstract

“…Historically, the structure HOOOH has been the subject of numerous quantum chemical studies of progressively higher level of sophistication (see Table ). Beginning with the first low-level ab initio studies of HOOOH by Plesničar et al and Blint and Newton in 1973, up to the most recent benchmark CCSD(T)-F12 calculations of Hollman and Schaefer (2012), all these studies confirmed a zigzag skew-chain helical-type structure with C 2 symmetry with HOOO dihedral angles equal and opposite to the global minimum. − ,,, As already mentioned above, in 2005, Endo and co-workers reported for the first time pure rotational spectra of HOOOH and determined unambiguously the precise geometrical structure of this polyoxide using FTMW spectroscopy and FTMW–millimeter-wave double- and triple-resonance spectroscopy. The calculated and experimental geometrical parameters for the most stable trans form of HOOOH are collected in Figure .…”

Section: Structure Acidity/basicity and Thermochemical Data Of Hydrog...mentioning

confidence: 84%

“…It was demonstrated that dihedral angles are crucial for determining the conformation of the polyoxides (HO n H, n = 2–4). , The hyperconjugation (also called “anomeric” effect), that is, delocalization of the oxygen pπ-type lone pair electrons into low-lying σ* orbitals of the adjacent O–H and O–O bonds by the optimal overlap of these orbitals, and the dipolar interaction effects were found to be predominant factors affecting the optimal dihedral angle in HOOOH. ,, The shortening of the O–O bond in the HOOOH, as compared to the O–O bond in HOOH, was also explained by hyperconjugation effects. The sensitivity of the dihedral angle in the polyoxides to replacement of H atoms by other elements (for example, F) supports these arguments (Figure ).…”

Section: Structure Acidity/basicity and Thermochemical Data Of Hydrog...mentioning

confidence: 99%

Recent Advances in the Chemistry of Hydrogen Trioxide (HOOOH)

Cerkovnik

Plesničar

2013

Chem. Rev.

View full text Add to dashboard Cite

General and theoretical aspects of the peroxide group

Cited by 11 publications

References 283 publications

Thermodynamics of Peroxynitrite and Its CO₂ Adduct

Thermodynamics of Peroxynitrite and Its CO₂ Adduct

Reaction of Organic Peroxyl Radicals with^•NO₂and^•NO in Aqueous Solution: Intermediacy of Organic Peroxynitrate and Peroxynitrite Species

Recent Advances in the Chemistry of Hydrogen Trioxide (HOOOH)

Contact Info

Product

Resources

About

General and theoretical aspects of the peroxide group

Cited by 11 publications

References 283 publications

Thermodynamics of Peroxynitrite and Its CO2 Adduct

Thermodynamics of Peroxynitrite and Its CO2 Adduct

Reaction of Organic Peroxyl Radicals with•NO2and•NO in Aqueous Solution: Intermediacy of Organic Peroxynitrate and Peroxynitrite Species

Recent Advances in the Chemistry of Hydrogen Trioxide (HOOOH)

Contact Info

Product

Resources

About

Thermodynamics of Peroxynitrite and Its CO₂ Adduct

Thermodynamics of Peroxynitrite and Its CO₂ Adduct

Reaction of Organic Peroxyl Radicals with^•NO₂and^•NO in Aqueous Solution: Intermediacy of Organic Peroxynitrate and Peroxynitrite Species