Mixed alkyl isocyanide-1,4-diaza-1,3-butadiene complexes of chromium—II. Secondary-ion, electron impact and chemical-ionization mass spectrometry of the 18-electron species Cr(CO) 3(CNR)(R′-DAB)

Mass analysis of the 18-electron mixed isocyanide-1,4-diaza-1,3-butadiene complexes [Cr(CO) 3(CNR)(R′-DAB)] (R = Me, CHMe 2, CMe 3 or xylyl; R′ = i-Pr, tBu or Cy) was undertaken using secondary-ion mass spectrometry (SIMS), electron impact (EI) mass spectrometry and both positive- and negative-ion c...

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Bibliographic Details
Published inPolyhedron Vol. 5; no. 8; pp. 1321 - 1328
Main Authors Detter, Lisa D., Walton, Richard A.
Format Journal Article
LanguageEnglish
Published Oxford Elsevier Ltd 1986
New York, NY Elsevier Science
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Summary:Mass analysis of the 18-electron mixed isocyanide-1,4-diaza-1,3-butadiene complexes [Cr(CO) 3(CNR)(R′-DAB)] (R = Me, CHMe 2, CMe 3 or xylyl; R′ = i-Pr, tBu or Cy) was undertaken using secondary-ion mass spectrometry (SIMS), electron impact (EI) mass spectrometry and both positive- and negative-ion chemical-ionization (CI) (PICI and NICI) mass spectrometry. With the exception of the PICI spectra, abundant molecular ions were not present. In all instances, well-defined, structurally informative fragment ions were identified which arise by loss of CO and/or the intact RNC and R′-DAB ligands. Cleavage of the RNC ligands (dealkylation) occurs in the SIMS and EI spectra to give fragment ions containing [Cr(CNH)] +, whereas only in NICI are fragments observed in which the cyano moiety [Cr(CN)] + is present. High-abundance carbonyl-containing fragments are seen only in the case of the CI spectra and are most common in the NICI measurements. These trends are discussed in the light of the Cr-ligand bonding.
ISSN:0277-5387
DOI:10.1016/S0277-5387(00)83123-X