Organotin mass spectroscopy

There are many references to the speciation of organotin compounds (particularly butyltin compounds) in marine sediments (see below), when compounds Uu Snk4 are separated by GLC or HPLC and analyzed by mass spectroscopy (MS),56 sometimes with isotope dilution.57-59... 

Organotin compounds, as well as being open to study by general spectroscopic techniques, e.g. UV, IR, and H and NMR spectroscopies as well as mass spectrometry, can also be investigated using such specific techniques as " Sn (or " Sn) NMR and " Sn Mdssbauer spectroscopies. The increasing availability of solid-state NMR spectroscopy provides further means of exploring stractures. 

The remark has been made that compounds of tin can be studied by more techniques than those of any other element. The fact that it has more stable isotopes that any other element gives it very characteristic mass spectra, and isotopic labelling can be used to interpret vibrational spectra, and for spiking samples in trace analysis two of the isotopes have spin 1/2 and are suitable for NMR spectroscopy, and their presence adds information to the ESR spectra of radical species. Further, the radioactive isotope 119mSn is appropriate for Mossbauer spectroscopy. The structural complications that are referred to in the previous chapter have therefore been investigated very thoroughly by spectroscopic and diffraction methods, and structural studies have always been prominent in organotin chemistry. 

Mossbauer spectroscopy is a powerful technique that may give information on the occurrence of tin and organotin polymeric structures. This is made possible through the investigation of molecular dynamics of " Sn nuclei embedded in molecular fragments and in particular through the well established correlation between the recoil free fraction of yrays (Debye-Waller-Mossbauer or Lamb-Mossbauer factor) and the mean square displacement of the nuclei (or of the masses bound to the Mossbauer nuclei). This correlation appears to be a linear dependence of the logarithm of the resonant peaks area, InA (proportional to Lamb Mossbauer factor,/ ) and the absolute temperature, T. 

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