A general synthetic strategy starting from metal alkyls is reported based on the hydrogen difluoride anion as a
suitable reagent for obtaining organometallic fluorides. The newly prepared compounds are [Me4N][(i-Bu)2AlF2]
(1), [Ph4P][(i-Bu)2AlF2] (2), and [Ph4P][AlF4] (3), containing the tetrahedral anions [(i-Bu)2AlF2]- and [AlF4]-.
The actual structures are prototypes that allowed a comparison of inorganic and organometallic fluorides in the
frame of the hard and soft acid and base principle, by means of ab initio calculations. A new theoretical model
is designed to put in equation form the qualitative statements of the Bent rule. The model allows the rationalization
of the tendencies of bond angle variation in [R2MX2] systems containing a main group metal (M), in terms of
hybridization of the central atom and the reciprocal influence of hard and soft ligands.