ISSN:
0947-6539
Keywords:
gas-phase chemistry
;
mass spectrometry
;
periodic trends
;
peroxides
;
transition-metal ions
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The bimolecular gas-phase reactions of d-block transition-metal cations M+ with dimethyl peroxide were screened by means of Fourier transform ion cyclotron resonance mass spectrometry. The rich chemistry can be classified into four types of reactions: i) Oxygen-atom transfer to generate MO+, ii) elimination of radicals, mostly CH3O·, iii) intramolecular redox reaction of dimethyl peroxide to form CH3OH, CH2O and CO, and iv) charge transfer from the metal cation to produce CH3OOCH3+. Some general trends became apparent from this study. For example, the “early” transition metals almost exclusively induce oxygen transfer to generate MO+, in line with the notoriously high oxophilicities of these metals, and electron transfer is only observed for Zn+ and Hg+. Both the radical loss and the disproportionation reaction emerge from a rovibrationally highly excited insertion intermediate (CH3O)2M+, and for the first-row metals the branching ratio of the competing processes seems to be affected by the M+—OR bond strengths as well as the electronic groundstate configurations of M+. For the 4d and 5d cations Ru+—Ag+ and Pt+—Au+, respectively, products resulting from intramolecular redox reactions dominate; this probably reflects the higher propensity of these metal ions to facilitate β-hydrogen atom shifts.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/chem.19950010907