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Thermal formation of mixed‐metal inorganic complexes at atmospheric pressure
Author(s) -
Peng WenPing,
Goodwin Mike P.,
Chen Hao,
Cooks R. Graham,
Wilker Jonathan
Publication year - 2008
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.3763
Subject(s) - chemistry , electrospray ionization , dissociation (chemistry) , metal , mass spectrometry , mass spectrum , protonation , cluster chemistry , inorganic chemistry , redox , metal ions in aqueous solution , cluster (spacecraft) , homonuclear molecule , ionization , chemical ionization , ion , molecule , organic chemistry , chromatography , computer science , programming language
Abstract Atmospheric‐pressure thermal desorption ionization (APTDI), a new variant on older ionization methods, is employed to generate gas‐phase ions from inorganic and organometallic compounds. The method is compared to conventional electrospray ionization (ESI) of these compounds and found in most cases examined to yield simpler mass spectra which are useful in the characterization of the pure compounds. Cluster formation, however, is prominent in these spectra and mixtures of V(IV)O(salen), Ni(II)(salen) and Co(II)(salen) show mixed‐metal cluster ions. This makes APTDI a way to prepare gas‐phase ions which contain multiple selected metal atoms and ligands. Such mixed‐metal complexes can be mass‐selected and structurally characterized by tandem mass spectrometry. Strong contrasts are evident in the dissociation behavior of homonuclear and heteronuclear metal clusters, the latter showing accompanying redox processes. The chemical reactivity accompanying collision‐induced dissociation (CID) of some of the mixed‐metal clusters is typified by the protonated species H + [NiVO(salen)], which undergoes a formal oxidation process (hydrogen atom loss) to give the molecular radical cation of Ni(salen). This ionization method may provide a new route to unique inorganic compounds on surfaces through soft landing of appropriate cluster ions. The contrasting behavior of the ESI and APTDI processes is evident in the salens where ESI shows simple Bronsted acid/base chemistry, no mixed‐metal clusters and no redox chemistry. Copyright © 2008 John Wiley & Sons, Ltd.