Menthane, monohydroperoxy derivative

Additional physico-chemical information

Administrative data

Endpoint:

other: bond dissociation energies

Type of information:

other: calculation of bond-strengths

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: published data, non GLP

Data source

Reference

Reference Type:

publication

Title:

A Reassessment of the Bond Dissociation Energies of Peroxides. An ab Initio Study

Author:

Robert D. Bach, Philippe Y. Ayala, H. B. Schlegel

Year:

1996

Bibliographic source:

J. Am. Chem. Soc. 1996, 118, 12758-12765

Results and discussion

Results:

The strength of the O-O bond is of fundamental importance in a variety of chemical processes.
Traditionally, a value of 34 kcal/mol has been ascribed to a generic O-O bond dissociation energy. The present, high-level ab initio calculations indicate that the average O-O bond energy is significantly higher, ca. 45 kcal/mol, and that the bond energy is sensitive to the bonding environment. Calculations at the G2 level of theory give bond dissociation enthalpies at 298 K of 50 kcal/mol for HOOH, 45 kcal/mol for CH3OOH, 39 kcal/mol for CH3OOCH3, and 48 kcal/mol for HC(O)OOH and CH3C(O)OOH. The G2(MP2) results are similar and, additionally, give bond dissociation enthalpies of 38 kcal/mol for diacetyl peroxide, 49 kcal/mol for trifluoroperoxyacetic acid, 23 kcal/mol for isopropenyl hydroperoxide, and 22 kcal/mol for peroxynitrous acid.

Any other information on results incl. tables

Generally Accepted Activation Parameters for Peroxide Bond Homolysisa
Peroxide	ΔH(kcal/mol)	ΔS[cal/(mol K)]
HO-OH	47	11
t-BuO-OH	41	12
RO-OR	36	14
PhCO-O-t-Bu	35	8
RCOO-OCOR	30	6
ROCO-OCOR	29	5

Referenced from:

Baldwin, A. C.Ibid.; p 97.

Curci, R.; Edwards, J. O. InCatalytic Oxidations with H2O2as oxidants; Strukul, G., Ed.; Series: Catalysis by Metal Complexes; Reidel-Kluwer: Dordrecht, The Netherlands, 1992; Chapter 3.

Applicant's summary and conclusion

Conclusions:

The strength of the O-O bond in peroxides decreases from 50 kcal/mol for HOOH, 45 kcal/mol for CH3OOH, 39 kcal/mol for CH3OOCH3, and 48 kcal/mol for HC(O)OOH and CH3C(O)OOH.

Executive summary:

The strength of the O-O bond is of fundamental importance in a variety of chemical processes with organic peroxides. Traditionally, a value of 34 kcal/mol has been ascribed to a generic O-O bond dissociation energy. The present, high-level ab initio calculations indicate that the average O-O bond energy is significantly higher, ca. 45 kcal/mol, and that the bond energy is sensitive to the bonding environment. Calculations at the G2 level of theory give bond dissociation enthalpies at 298 K of 50 kcal/mol for HOOH, 45 kcal/mol for CH3OOH, 39 kcal/mol for CH3OOCH3, and 48 kcal/mol for HC(O)OOH and CH3C(O)OOH. The G2(MP2) results are similar and, additionally, give bond dissociation enthalpies of 38 kcal/mol for diacetyl peroxide, 49 kcal/mol for trifluoroperoxyacetic acid, 23 kcal/mol for isopropenyl hydroperoxide, and 22 kcal/mol for peroxynitrous acid.