F-C-F = 109.5°
tried to reproduce this value on my Spartan software, but failed , both with MM based and with Hartree-Fock based energy optimizing algorithms
sure this isn't a typo ? ( 11
9,5° would be just fine with me instead)
with respect to bond angels in Br-C-Br :
- [itex]\sigma[/itex] bonds are a little shorter than p- sp3
- [itex]\sigma[/itex] bonds.
Br - atoms being slightly obese, they yell for distance from each other, and, being attached to the same carbon, hence for longer bonds Br - C (as this is the only game in town)
this repulsive effect makes the "clean" sp2
hybridization not the most optimum energetic solution for the system.
Instead, a "broken" hybridization of the sp(2+x)
type ; 0 < x <1 is the optimum for the system
... and this increased p- character makes for different bond angels, more towards 109,5° ( i.e. towards sp3