Fluorine-19 Nuclear Magnetic Resonance.

A detailed investigation of the reaction of a series of pyridines with titanium tetrafluoride has been carried out with high-resolution fluorine-19 nuclear magnetic resonance spectroscopy. Instead of the formation of only simple diadducts a mixture of products is found in the solvent acetonitrile. The main species are TiF4 - 2D, TiF3 - 3D(+) and TiF5 - D(-). An extensive series of TiF5 - d(-) complex ions is studied by (19)F nmr. Linear correlations of the chemical shifts of the fluorines in TiF4 - 2D and TiF5 - D(-) complexes are found with the pKa values of the substituted pyridines. Some complexes of TiF4 with bidentate ligands are reported as well as some products with sulfur containing ligands. Fluorine-19 nmr data are also given for some GeF4 - 2D adducts where D represents some substituted pyridine 1-oxides. Geometrical isomers were found with GeF4 - 2D compounds and both first and second order nmr spectra were measured. (Modified author abstract)