Thermochemical kinetics of bromine nitrate, bromine nitrite, halogen hydroperoxides, dichlorine pentoxide, peroxycarboxylic acids, and diacyl peroxides

Chlorates and perchlorates as potential high-energy materials: chlorate- and perchlorate-substituted methanes

The structures and properties of thirty-three of the thirty-four possible chlorato-Cl-, chlorato-O- and perchlorato-derivatives of methane have been computed using the range-separated hybrid generalized gradient approximation density functional method ωB97X-D with the 6-311+G(2d,p) basis set. These results indicate that the chlorato-O-substituent confers more stability to a molecule than does the chlorato-Cl-substituent; the perchlorato-substituent is approximately intermediate in this regard when decomposition energies are calculated. The C–Cl bond lengths in the chlorato-Cl-substituents generally elongate and the C–O distances in the chlorato-O- and perchlorato-substituents tend to shorten as the number of chlorate/perchlorate substituents increases. In addition, as the C–O bond shortens, the CO–Cl bond lengthens. The calculated Mulliken and Löwdin bond orders for these bonds exhibit the opposite of the trends exhibited by the bond lengths, as expected: As the bond lengthens, the bond order decreases, and vice versa. The single molecule that could not be optimized as a stable methane derivative, (chlorato-Cl-)tris(chlorato-O-)methane, rearranged during all optimization attempts to an isomer of the neutral Cl₂O₅ molecule and a hitherto unknown molecule, bis(chlorato-O-)carbonyl, (O₂ClO)₂C=O.

THEORETICAL STUDY ON OXYGEN–OXYGEN HOMOLYTIC BOND DISSOCIATION ENTHALPIES OF PEROXIDES

Seven theoretical methods (B3LYP, B3P86, X3LYP, BMK, MP2, CBS-QB3, G3B3) were employed to calculate oxygen–oxygen homolytic bond dissociation enthalpies of 13 peroxides. Comparison of the performances of these methods with the available experimental data showed that ROBMK method is suitable and economical for calculating O–O homolytic bond dissociation enthalpies of peroxides. Then ROBMK method was used to calculate O–O homolytic bond dissociation enthalpies of a series of peroxides. Meanwhile, the α-substituent effect and Hammett relationship were also discussed.