Crystal Field split of Trigonal Planar complex?

Question

What would a "HYPOTHETICAL" splitting of the D ORBITALS in a trigonal planar complex be? (Dxy, Dxz...etc.)
Can you please give the order in lowest to highest energy?

Answer 1

"Crystal Field Splitting can be defined only for tetrahedral and octahedral complexes." Raymond Chang; Physical Chemistry for the chemical and biological sciences; Univ. Science Books, Sausalito CA; 2000; P.652

Answer 2

Tips: You have to be able to visualize this in your brain in 3D. and it is kinda hard! To answer your question i'm gonna use an example of metal-ligand interaction. In tetrahedral complex, all the d orbitals of the metal complex are not degenerate. dxy, dyz and dxz have higher energy level than dx2-y2 and dz2. Why is this so? It has all to do with the orientation of the d orbitals and the direction of the incoming ligands. Initially, all the d orbitals in the metal are degenerate. When the ligands approach for bond formation ie 4 ligands will come from 4 corner of tetrahedral shape (109.5 degree of each other). d orbitals of the metal will split. Crystal field theory explain that the orbitals that face the direction of the ligand (dxy, dyz and dxz) will be pushed to higher energy level whereas the orbitals that are not facing the direction of the ligand (dx2-y2 and dz2) will not be affected and stay at the same level. Another tips: Try draw each of the d orbitals with the incoming ligand from 4 directions to make tetrahedral complex. it helps! :D (Molecular orbital theory should be more interesting though)