Premium
On the Oxenoid Character of Alkylperoxy Anions and Their Lithium Compounds: A Combined Mass‐Spectrometric and Theoretical Investigation
Author(s) -
Schalley Christoph A.,
Schröder Detlef,
Schwarz Helmut,
Möbus Konrad,
Boche Gernot
Publication year - 1997
Publication title -
chemische berichte
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 0009-2940
DOI - 10.1002/cber.19971300810
Subject(s) - chemistry , reactivity (psychology) , moiety , medicinal chemistry , mass spectrum , formaldehyde , lithium (medication) , ion , decomposition , stereochemistry , organic chemistry , medicine , alternative medicine , pathology , endocrinology
A combined mass‐spectrometric and theoretical approach has been used for an investigation of the gas‐phase chemistry of two representative alkylperoxy anions. Metastable CH 3 OO − ions undergo unimolecular loss of molecular hydrogen and formaldehyde yielding HCO − 2 and OH − , respectively. The observed reactivity is in pleasing agreement with calculations of the [C,H 3 ,O 2 − and [C,H,O 2 ] ‐ potential‐energy surfaces at the BECKE3LYP/6‐311+ + G ** level of theory. Upon exhaustive methylation of the α‐position as in t ‐C 4 H 9 OO − anions, the reactivity switches completely to an elimination of (CH 3 ) 2 CCH 2 giving rise to the formation of HOO − . The results obtained for the “bare” alkylperoxy anions are used for the analysis of the EI mass spectrum of ( t ‐C 4 H 9 OOLi) 12 dodecamers, which thermally decompose in the inlet system at a probe temperature of ca. 130°C. The decomposition is rationalized by a mechanism involving nucleophilic attack of one t ‐C 4 H 9 OOLi subunit on the oxenoid oxygen atom of a second t ‐C 4 H 9 OOOLi moiety. This reaction may produce t ‐C 4 H 9 OOOLi trioxy species as intermediates, which rapidly decompose to singlet dioxygen and t ‐C 4 H 9 OLi.