Degradation of ionized OV(OCH3)3 in the gas phase. From the neutral compound all the way down to the quasi-terminal fragments VO+ and VOH+.
The consecutive fragmentation of ionized trimethyl vanadate(V), OV(OCH3)3 (1), is examined by experiment and theory. After an elimination of formaldehyde from the molecular ion 1+, subsequent dissociations proceed via losses of first H2 and then two molecules of formaldehyde to finally yield the VOH+ cation; these redox reactions involve the V(II)/V(IV) manifold. At elevated energies, expulsion of CH3O* from 1+ can efficiently compete to afford OV(OCH3)2+, a formal V(V) compound, from which subsequent losses of H2 and two units of CH2O lead to bare VO+, thereby exploring the V(III)/V(V) redox manifold. Experiments using complementary mass spectrometric techniques, i.e., neutralization-reionization experiments and ion/molecule reactions, in conjunction with extensive computational studies provide deep insight into the ion structures and the relative energetics of these dissociation reactions. In particular, a quantitative energetic scheme is obtained that ranges from neutral OV(OCH3)3 all the way down to the quasi-terminal fragment ions VOH+ and VO+, respectively.
Schröder
Detlef
D
Institute for Organic Chemistry and Biochemistry, Czech Academy of Sciences, 16610 Prague 6, Czech Republic. detlef.schroeder@uochb.cas.cz
Engeser
Marianne
M
Schwarz
Helmut
H
Rosenthal
Esther C E
EC
Döbler
Jens
J
Sauer
Joachim
J