What is the molecular shape of #PF_3#?

1 Answer
Jun 4, 2016

Answer:

#"Trigonal pyramidal"#

Explanation:

There are 4 regions of electron density around the central phosphorus atom, one of which is a lone pair. Given simple VSEPR, a structure based on a tetrahedron is specified. But because we describe structure in relation to atoms, and not electron pairs, the structure of #PF_3# should be pyramidal, an analogue of ammonia.

This site reports that #/_F-P-F=107""^@#, so it seems that we are not too offbase. The #/_F-N-F=102.5""^@# in #NF_3# is included for comparison.