X-ray and spectroscopic studies of organotin compounds.

A critical survey of organotin chemistry and an outline of the determination of crystal structures by X-ray analysis have been made. Crystallographic and spectroscopic studies have been made of novel organotin compounds, allowing comparison of solid and solution phase structures to be made. Rationalisation of reactivities has also been made from the data. Crystal structures of the alpha-substituted compounds, Ph3SnCH2OC6HMe-p, Cy3SnCH2SC6H4Cl-p, Ph3SnCH2SeC6H4OMe-m and 1-(Ph3SnCH2)-triazole revealed that the tin atoms had slightly distorted tetrahedral geometries. Despite the short Sn--Y distances (Y=0, S, Se or N), there is no evidence for Sn-Y coordination. By contrast, in [1-(XPh2SnCH2)-triazole]n (X=I, n=4; X=Br, n=2), the tin atoms have trigonal bipyramidal geometries with definite Sn--N linkages. Pentacoordinate tin atoms have also been found in the following: ClPh2SnCH2CH2CH2SC6H4Me-p (1), ClMe2SnCH2CH2CH2PPhBut (2) and 3-C-(dibutyliodostannyl)methyl-l,2:5,6-di-Omicron-isopropylidene-alpha-D-allofuranose (3). In methyl 4,6-Omicron-benzylidene-3-deoxy-3-triphenylstannyl-alpha-D-altro-pyranoside, the bond angles about tin are close to tetrahedral; however, there are two non-bonding Sn---0 distances of ca 3.2 Â. The enhanced reactivity of the Ph-Sn bond towards iodine can be explained in terms of nucleophilic assistance provided by these oxygen atoms. The solid state conformation of Ph3SnCH(SCN)CH2SC6H4NO2-omicron is staggered; the tin and beta-sulphur atoms are in a gauche arrangement which suggests a weak Sn---S(beta) interaction. In solution, this conformation is populated for only a third of the time. The tin geometry is between tetrahedral and cis-trigonal bipyramidal in Ph3Sn(O2CC6H4NO2-rho), and skew-trapizoidal in Bu2Sn(O2CC6H4NO2-rho)2. Spectroscopic data for {[(m- or omicron-O2NC6H4CO2)SnBu2]02} indicate two distinct tin environments. Crystal structures determinations of [Bu4N][Me2C1Sn(DMIT)] (4), [Bu4N] (SnR(DMIT)2] (R=Bu or Ph) (5) and [Bu4N][Sn(I2)(DMIT)2] (6) (H2DMIT = 4,5-dimercapto-l,3-dithiole-2-thione) revealed that the geometries about tin are trigonal bipyramidal (4), rectangular pyramidal (5) and pseudo-octahedral with cis diiodo groups (6).

Grantor dc:publisher.institution

Robert Gordon's Institute of Technology

Year dc:date.issued

1992

Author dc:creator

• Doidge-Harrison, Solange Maria Silva Veloso

Advisor dc:contributor.advisor

• P.J. Cox, J.L. Wardell, R. A. Howie and I.W. Nowell

• Organotin compounds
• X-ray analysis
• Crystal structures
• Crystallographic studies
• Spectroscopic studies
• Phase structures
• Tin atoms
• Tetrahedral geometries
• Trigonal bipyramidal geometries

Language dc:language

en

Identifier

oai:rgu-repository.worktribe.com:2807365
https://doi.org/10.48526/rgu-wt-2807365

OAI identifier oai:identifier

oai:rgu-repository.worktribe.com:2807365