119Sn Mossbauer

Organotin(IV) compounds are Lewis acids. The crystalline structure of Lewis acid-base adducts between compounds R SnCl4- (/ = 0,..., 3) and Ni complexes with Schiff bases was determined by XRD, 119Sn Mossbauer and IR spectroscopy. Adducts are formed in 1 1, 1 2 and 2 1 ratios121. 

Me3SnCl (33) 119Sn Mossbauer. The frozen solid compound is polymeric, while die compound isolated in a low-temperature argon matrix is monomeric as in die gas phase. Frozen solutions in polar solvents show significant solvent solute interactions. Compare to behaviour of compound 79 in Table 8. 154... 

Polymeric trigonal bypiramidal Sn structure 221 with trans O—Sn—O binding. Also variable-temperature 119Sn Mossbauer spectroscopy (see compound 50 in Table 5). These compounds are important pesticides. 

In contrast to the above systems, where electronic support interactions were negligible, the work of Bowles and Cranshaw 198) points to the presence of such effects for tin on platinum. Tin was deposited on platinum electrodes at a potential high enough to ensure a fractional tin monolayer. Subsequent 119Sn Mossbauer spectroscopy showed a tin isomer shift characteristic of a Pt-Sn alloy, thereby evidencing the electronic interaction between these two metals. The possible modification by the support of the... 

Sn Mossbauer spectroscopy has been used to a limited extent to characterize some of the tin complexes described herein. A table of isomer shifts is provided here, but it is clear that much more data are required before any trends might emerge. 

Onaka, S., Sasaki, Y. and Sano, H. (1971b) 119Sn-Mossbauer and ll- and 55Mn-NMR spectroscopic studies of a series of compounds, R3 xXxSn-Mn(CO)5. Bull. Chem. Soc. Jpn., 44, 726-730. 

Hypervalent compounds with coordinative phosphorus —> tin bonds are rare. An intermolecular P —> Sn coordination in Me2ClSnCH2CH2PPh2 and its bromo-substituted analogue was suggested based on NMR and 119Sn Mossbauer spectroscopic data201,202. The X-ray crystal structure analyses showed pentacoordinate tin atoms with the phosphorus and the chlorine atoms located in axial positions203. The P —> Sn distance amounts to... 

Hi. Intermolecular Sn—0(ketone) interactions. l,4-dimethylpiperazine-2,5-dione is the simplest cyclic peptide, which was used to study adducts with SnCLj, BuSnCl3, Me2SnCl2 and Ph2SnCl2 by 119Sn Mossbauer and IR spectroscopy295. The crystal structure analysis of the 1 1 complex of Ph2SnCl2 and l,4-dimethylpiperazine-2,5-dione (138) revealed an infinite polymeric zigzag chain, in which the octahedrally coordinated tin atoms are... 

Tin Mossbauer. 119Sn Mossbauer data also provide a bulk diagnostic and this method has been utilized in a number of studies (for example, 7,26-39). Direct evidence for PtSn alloy formation was obtained from Mossbauer studies (for example, 7,34,35,38,39) however, many of these studies were at high metal loadings and even then a complex spectrum was obtained so that there was some uncertainty in assigning Sn(0) to the exclusion of tin oxide phases. 

Through the combined use of catalytic probe reactions, Mossbauer, EXAFS, XPS, XRD, it has been demonstrated that the anticipated particle structures for the half-SMAD and full SMAD procedures are close to reality.(40-42) Thus, 119Sn Mossbauer, a bulk solid analysis technique, revealed the relative amounts of Sn, Pt-Sn alloy, SnO, and Sn02 present in the catalysts. It was possible to differentiate Sn° from Pt-Sn alloy through supporting evidence of XPS and selective oxidation, since it was found that ultra-fine Sn° particles were much more susceptible to oxidation than Pt-Sn alloy particles. Also, since the full SMAD Pt°-Sn°/Al203 catalysts behaved much differently than Pt°/Al203, it is clear that the SMAD catalysts are not made up of separate Pt° and Sn particles. 

Figure 10. 119Sn Mossbauer Spectra for (1) j3-Sn foil (2) bulk AuSn alloy (3) Sn particles prepared in acetone (4) AuSn particles prepared in acetone...

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