Phosphorus can form the molecular compound PF₃Cl₂, in which the five substituents occupy the positions of a trigonal bipyramidal electron-density arrangement.
(a) Draw all possible nonequivalent three-dimensional arrangements of three F atoms and two Cl atoms around the central P atom that satisfy this geometry. Clearly label axial and equatorial positions in each arrangement.
(b) Considering relative ligand sizes and inter-ligand repulsions, determine which arrangement is predicted to be most stable. Provide a chemical justification for your choice.
(c) Give the name of the molecular shape (based solely on the positions of the atoms, not the electron regions) adopted by PF₃Cl₂ in the preferred arrangement.
(d) Predict whether PF₃Cl₂, in its preferred arrangement, has a nonzero net molecular dipole moment. Support your prediction by analyzing both individual bond dipoles and molecular symmetry.
(a) Possible three-dimensional arrangements
(b) Selection and justification of the most stable arrangement
(c) Name of molecular shape
(d) Dipole moment prediction with justification