A Photoelectron Investigation of the Peroxide Bond

Abstract

R. S. BROWN. Can. J. Chem. 53,3439 (1975). The photoelectron spectra of several peroxides and their interpretation is presented. The effects of substituents is separated from vicinal orbital interactions using as a guideline the effect of similar substitution on the ether analogues. It is found that by comparison of Raman spectroscopic frequencies of the peroxide ground state, and vibrational frequencies for the ion (via pes), that the HOMO of peroxides is antibonding with respect to the 0-0 linkage. Additionally, the dependence of the splitting of the two highest occupied molecular orbitals on dihedral angle is verified by the pe spectra of several well-defined cyclic peroxides. Finally, the pe spectrum of tetramethyl-1,2-dioxacyclobutane (tetramethyl dioxetane) is presented indicating that it is not unlike other cyclic peroxides.

A theoretical and experimental study on the molecular and electronic structures of artemisinin and related drug molecules

“…(iv) The top two E i s of MTP are mainly due to the lone pairs localized on the lactol pyran oxygen (O pyr ) and acetal oxygen (O Me ), respectively. Incidentally, it can be noted that the present OVGF results corroborate the semiempirical assignment proposed in earlier photoelectron studies on peroxides[71][72][73][74][75].…”

The infrared spectrum of HOOH+ trapped in solid neon

“…The low-lying a 1 A state of HO 2 + may play a significant role in the observed broadening. Their B3LYP calculations of the positions of the fundamental vibrations of ground-state HO 2 + yielded values which agreed well with the values (ν 1 = 3066.6, ν 2 = 1071.5, ν 3 = 1361.6 cm −1 ) subsequently obtained in the anharmonic MRCI calculations by Robbe and co-workers. 45 The multi-reference configuration interaction (MRCI) study also determined that the origin of theã 1 A state of HO 2 + should lie only about 1185 cm −1 above the ground-state origin.…”

“…Their observations determined that the first excited state of HOOH + lies approximately 16 800 cm −1 above the onset of ionization and its second excited state approximately 38 400 cm −1 above that onset. Later photoelectron studies by Brown 2 and by Ashmore and Burgess 3 confirmed those values and yielded an adiabatic ionization energy of 10.62 eV for the uncharged molecule. More recently, photoionization measurements by Litorja and Ruscic 4 refined the value for the first ionization energy of HOOH to 10.631(7) eV.…”

“…The first information about the vibrational spectrum of H 2 O 2 + was obtained from the photoelectron spectroscopic experiments of Brown and co-workers 2 and of Ashmore and co-workers, 3 who assigned structure in the ground-state photoelectron band to a progression in the totally symmetric deformation fundamental with a spacing of 1080(50) cm −1 . Analysis of the infrared study of H 2 O 2 + -d n reported in this paper was facilitated by calculations of the isotopic substitution behavior of the vibrational fundamentals of trans-HOOH + using the GAUSSIAN 09 program package.…”

O—O stretching frequencies of cyclic peroxides. Stabilization of peroxides by alkoxy substituents

“…P. Schaap, acetone (27) and cyclohexanone (28) diperoxides were prepared as described, tetramethoxyethylene was oxygenated (3) to prepare the dioxetane, the other dioxetanes were available from previous studies (23,25) and the other peroxides were prepared by Prof. R. S. Brown (29).…”