Structural aspects of organic peroxides

Gougoutas, Jack Z.

doi:10.1002/9780470771730.ch12

Cited by 4 publications

(3 citation statements)

References 127 publications

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“…In the case of molecules with peroxo and superoxo groups, the existence of OO bonded interactions is well-established. The OO bonds in the latter groups are typically short (∼1.30 Å), whereas those of the peroxo groups are somewhat longer and fall, for the most part, in the range between 1.45 and 1.50 Å .…”

Section: Bond Critical Points Between Oxide Anionsmentioning

confidence: 99%

Model Structures and Electron Density Distributions for the Silica Polymorph Coesite at Pressure: An Assessment of OO Bonded Interactions

et al. 2000

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The crystal structure and the bond critical point, bcp, properties of the electron density distribution for the high-pressure silica polymorph coesite were generated for pressures up to ∼17 GPa, using first-principles calculations. The nonequivalent SiO bond lengths and the SiOSi and OSiO angles of the generated structures agree with those observed to within ∼1%. With compression, the SiO bond lengths and the variable SiOSi angles of the structures both decrease while the value of the electron density, ρ(r c), the curvatures, and the Laplacian of the electron density distribution at the bond critical points each increases slightly. As found in a recent modeling of the structure of low quartz, the calculated electron density distributions are nearly static and change relatively little with compression. The bcp properties of the model structure agree with those observed at ambient conditions to within ∼10%, on average, with several of the properties observed to correlate with the observed SiO bond lengths, R(SiO). This agreement is comparable with that observed for several other silicates. As predicted, the bonded radius of the oxide anion, the curvatures of ρ(r c) paralleling the bond paths and the Laplacian of ρ(r c) each correlates with the observed bond lengths. However, the observed ρ(r c) values and the curvatures of ρ(r c) perpendicular to the paths fail to show a correlation with the observed bond lengths. The ellipticity of the SiO bonds in both the model and the observed structures tends to decrease in value as the SiOSi angle approaches 180°, indicating that the bonds become more circular in cross sections as the angle widens. Ridges of electron density and bond critical points were found between the intertetrahedral oxide anions at each pressure. The existence of these features appears to be closely related to purely geometrical factors of the coesite structure rather than to bonded interactions. None of these features was found between the intratetrahedral oxide anions.

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Section: Bond Critical Points Between Oxide Anionsmentioning

confidence: 99%

Model Structures and Electron Density Distributions for the Silica Polymorph Coesite at Pressure: An Assessment of OO Bonded Interactions

et al. 2000

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“…Steric bulk around the COOC units is compensated differently in 8 and Ph 3 COOCPh 3 , however: bis(triphenylmethyl)peroxide has a “normal” O–O bond length (148.0 pm), , but elongated C–O (146.1 pm) and C–C ar distances (153.3 pm). In contrast, the solid-state structure of 8 is characterized by normal C–O (140.6 pm) and C–C ar bond lengths (152.5 pm), but an unusually long O–O bond (151.3 pm), which is significantly longer than the usually observed O–O bond lengths in other dialkyl peroxides (145–146 pm). , Packing effects may account for these structural differences, because the solid-state structure of 8 shows motifs of intermolecular π–π stacking, which are not found in the crystal structure of bis(triphenylmethyl)peroxide [see the Supporting Information (SI)].…”

mentioning

confidence: 94%

“…As in the solid-state structure of bis(triphenylmethyl)peroxide, , 8 has a center of inversion in its crystal structure and a C–O–O–C dihedral angle of 180°. Steric bulk around the COOC units is compensated differently in 8 and Ph 3 COOCPh 3 , however: bis(triphenylmethyl)peroxide has a “normal” O–O bond length (148.0 pm), , but elongated C–O (146.1 pm) and C–C ar distances (153.3 pm).…”

mentioning

confidence: 99%

Nucleophilic Reactivities of Bleach Reagents

Mayer

Ofial

2018

Org. Lett.

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The nucleophilicities of the oxidants hydroperoxide, hypochlorite, hypobromite, bromite, and peroxymonosulfate were determined by following the kinetics of their reactions with a series of benzhydrylium ions of known electrophilicity ( E) in alkaline, aqueous solutions at 20 °C. The reactivities of the oxidants correlate only weakly with their basicities. Analyzing the rate constants by using the relationship log k = s( N + E) gave the parameters N (and s), which were applied to predict the rates of Weitz-Scheffer epoxidations.

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