Structural Organotin Chemistry

Sn type RjSnX type RjSnX, type RSnXj type 

type riS RjSnXj type ris-R2SnX3 type RS11X4 type 

The tetraorganotin compounds, R4Sn, show no tendency to increase their coordination number, owing to their weak, Lewis acidity conferred by the four electron-releasing alkyl groups. It has, however, been claimed (353) that trimethyl(trifluoromethyl)tin forms a 1 1 adduct with hexamethylphosphoric triamide, and that this may be isolated in the solid state. 

If the ligand X2 in a pentacoordinate triorganotin compound is potentially bidentate, such as the anion of l,3-diphenyl-l,3-propanedione or of A -benzoyl-iV-phenylhydroxylamine, the tin atom is constrained to a cis-RsSnX type of geometry, e.g., the triphenylstannyl derivatives of 

It is quite probable that, in the monoorganostannatranes, RSniOCHjCHjlgN, the tin atom also occupies a trigonal, bipyramidal geometry, but with the organic group forced into an axial site 195, 

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Recently, Ho and Zuckerman have published an extensive review 65) on structural organotin chemistry and discussed the experimental evidence accumulated up to 1971. The number of papers devoted to organotin structures has increased 13, 19, 20, 23, 59, 60, 74, 125, 127) lately, the increase being markedly favored by progress in electronic and X-ray hardware. The bond lengths and angles obtained are very important for correlations with the spectral evidence (57). Such correlations may make other spectral evidence quite reliable even in the absence of the respective diffraction data. 

The lattice structures for organogermanes are predominantly molecular, with only isolated examples of associated lattices arising from intermolecular polymerization (112, 152,168). It is, perhaps, surprising that so few examples exist in this area of chemistry in which molecular ordering signifies the onset of lattice association which is so common in organotin chemistry (49, 185). 

Redistribution Equilibria of Organometallic Compounds, 6, 171 Radiochemistry of Organometallic Compounds, 11, 207 Strengths of Metal-to-Carbon Bonds, 2, 49 Structural Aspects of Organotin Chemistry, 5, 137 Structural Chemistry of Organo-Transition Metal Complexes, 3, Structures of Organolithium Compounds, 3, 365 Transition Metal-Carborane Complexes, 8, 87 Transition Metal-Isocyanide Complexes, 11, 21... 

General books, reviews, and monographs cover the field of organotin chemistry. Usefiil review articles on NMR spectroscopy, Mossbauer spectroscopy, and crystal structures of tin compounds have also been published. 

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. 

R. C. Poller, Organotin Chemistry, Logos Press, 1970 W. P Neumann, The Organic Chemistry of Tin (transl. R. Moser), Wiley, 1970 R. Okawara and M. Wada, Ado. Organometallic Chem., 1967, 5, 137 (structural aspects of organotin compounds) A. G. Davies, Chem. in Britain, 1969, 403 (a short review). 

Compounds of tin are studied by more teehniques than those of any other element. Beside the other conventional methods, some of the more specialized techniques are also well-suited to solve structural problems in organotin chemistry. The fact that tin has more stable isotopes than any other element gives it very characteristic mass spectra and these isotopes give rise to... 

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