Trialkoxy Tellurium Trifluorides

Trialkoxy tellurium trifluorides may exist as/ac-isomers (three fluorine atoms define a face of the octahedron) and as mer-isomers (three fluorine atoms at three corners along the circumference). The compounds are colorless liquids or solids. Although many trialkoxy tellurium trifluorides have been observed by F-NMR spectroscopy to be present in reaction mixtures, only a few were isolated in pure form. 

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Tellurium hexafluoride when heated with at least 4.5 molar equivalents of a primary alcohol at 90° for nine days in the presence of a large excess of sodium fluoride, produced mixtures of alkoxy tellurium fluorides. Among these fluorides were fac- and nzer-trialkoxy tellurium trifluorides. The compounds were identified by 19F-NMR spectroscopy1. The reactions were carried out as described on page 123. 

Dialkoxy tellurium tetrafluorides may react in chloroform with an excess of alcohol in the presence of pyridine to form trialkoxy tellurium trifluorides. Whether or not these reactions produce trialkoxy tellurium trifluorides depends on the nature of the alkoxy groups in the dialkoxy tellurium tetrafluoride and only secondarily on the nature of the alkyl groups of the alcohol. 

Trialkoxy Tellurium Trifluorides/Diamino Tellurium Tetrafluorides... 

The reaction mixtures were treated with water and the chloroform layers separated. The solvent was removed from the dried organic phases and the residues distilled under reduced pressure. The constitution of the products was confirmed by 19F-NMR spectroscopy. The trialkoxy tellurium trifluorides were found to be mixtures of the fac- and mer-isomers1. 

Dialkoxy tellurium tetrafluorides reacted with primary monohydric alcohols to give trialkoxy tellurium trifluorides. ... 

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