The same procedure can be used to derive the fact that the inplane
F 2p orbitals combine to give two LGOs with a1’ and
a2’ symmetries respectively, and two sets of e’ LGOs. These
are shown schematically in Figure 4.22 as LGOs (4), (6),
(7), (10), (11) and (12).
We are now in a position to construct a qualitative MO
diagram to describe the bonding in BF3. The symmetries of
the B orbitals under D3h symmetry are given at the left side
of Figure 4.23, and those of the LGOs are shown in Figure
4.22. The problem is best tackled in three steps:
. look for orbital interactions that give rise to -MOs;
. look for orbital interactions that give rise to -orbitals;