Metastable ion study of substituted cyclopentadienylmanganese cations in the gas phase

✍ Scribed by Dmitri V. Zagorevskii; Yurii S. Nekrasov; John L. Holmes

• Book ID: 103995764
• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 663 KB
• Volume: 4
• Category: Article
• ISSN: 1044-0305
• DOI: 10.1016/1044-0305(93)85084-b

✦ Synopsis

The behavior of some substituted cyclopentadienylmanganese ions has been studied by tandem mass spectrometry. This metastable ion study showed that only C5H5Mn(+) and (C5H4CN)Mn(+) ions retain their nido-cluster structure (1), which is characterized by a simple metal-ligand bond cleavage. Other substituted ions, RXC5H4Mn(+), rearrange to a different extent, depending on the nature of the substituent. The first rearrangement step is R radical migration to the central metal atom, leading to RMnC5H4X(+)-type ions (2). These ions decompose by elimination of X (for X=CO) or with formation of RMnX(+), but further rearrangements can also occur. These are the reverse migration of R from the metal atom to the π-ligand (for R=H, Ph) and cyclopentadienyl ring expansion (for X=CH2). Collisional activation mass spectra contained an Mn(+) ion peak, which can indicate the existence of stable type 1 structures for most cyclopentadienylmanganese ions. Carboxyl and hydroxymethyl derivatives exist, presumably as ions of type 2. The neutralization-reionization mass spectra of RXC5H4Mn(+) ions are also discussed.