Thermal formation of mixed-metal inorganic complexes at atmospheric pressure

Wen Ping Peng, Mike P. Goodwin, Hao Chen, R. Graham Cooks, Jonathan Wilker

Research output: Contribution to journalArticlepeer-review

14 Scopus citations


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.

Original languageEnglish (US)
Pages (from-to)3540-3548
Number of pages9
JournalRapid Communications in Mass Spectrometry
Issue number22
StatePublished - Nov 30 2008
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Analytical Chemistry
  • Spectroscopy
  • Organic Chemistry


Dive into the research topics of 'Thermal formation of mixed-metal inorganic complexes at atmospheric pressure'. Together they form a unique fingerprint.

Cite this