Comparison of the tandem mass spectrometry analysis of compounds of general structure R2R?SnPh, RR?SnPh2 with R4Sn analogues

Abstract

Positive ion-electron impact (EI) mass spectra of some novel organotin compounds have been recorded. These compounds were of the type Me 2 SnRR' (where R = Me, Ph and R' = Ph) and R 2 R'SnPh (where R = Me, n-Bu, n-Pe and R' = Me, n-Bu, n-Pe). The spectra were also examined by tandem mass spectrometry (MS-MS) in order to establish fragmentation reaction mechanisms for compounds bearing mixed substituents, particularly the effect of the presence of aryl substituents. In addition, the resultant EI and MS-MS spectra for these compounds were compared with those of R 4 Sn (R = Me, Bu, Pe, Ph). The results show that mixed substitution of tetra-alkyl/aryl compounds has a significant effect on the behaviour of these compounds in the mass spectrometer. This effect can be illustrated by examining the fragmentation reaction pathways for the various compounds studied. Fragmentation patterns of nine organotin compounds, based on precursorproduct ion relationships are proposed. This technique has the potential to predict the effect of substitution on the mass spectra of organotin compounds and probably organolead and organogermanium compounds.

Structural analysis of 2,6‐[bis(alkyloxy)methyl]‐phenyltin derivatives using electrospray ionization mass spectrometry

“…Some alkyls prefer the NL of alkenes ( tert ‐butyl and isopropyl), whereas others favour the loss of alcohols and aldehydes (methyl and ethyl). Concerning the oxidation state of tin, it is changes between Sn(IV) and Sn(II) in agreement with previous studies performed with either ESI21, 28 or EI 24–27. Almost all observed ions are even‐electron ions with rare exceptions, e.g.…”

“…Before the advent of ESI, the conventional electron ionization (EI) was the ionization technique of choice in the analysis of more volatile organotin compounds. EI fragmentation patterns of simple organotin compounds with one to four aryl or alkyl substituents have been described 24–27. The typical neutral losses are alkenes and the majority of fragment ions are even‐electron ions except for the molecular radical‐cation M +• and diaryl‐ and dialkyltin radical ions, which are similar to those in soft ionization techniques.…”