Question

5. Consider an hypothetical six-coordinate complex SH6 with the sulfur atom located at the center of a trigonal prism as shown below. (a) What is the point group symmetry of this complex? (b) What are the symmetries of the ligand group orbitals of a trigonal prismatic SHE? (c) Construct a molecular orbital energy diagram for trigonal prismatic SH6. Please include the valence electrons in your diagram. (d) Will the molecule be expected to be stable?

Answer 1

the trigonal prismatic molecular geometry describes the shape of compounds where six atoms, groups of atoms, or ligands are arranged around a central atom, defining the vertices of a triangular prism.

(W(CH₃)₆) was the first example of a molecular trigonal prismatic complex. The figure shows the six carbon atoms arranged at the vertices of a triangular prism with the tungsten at the centre.

a)point group is D_3h

B)contains a C₃ main rotation axis and 3 perpendicular C₂ axes. There are 3 σ_v planes and a σ_h plane. Hence belongs to the D_3hpoint group.

For D_3h geometry, the four characteristic vibrational modes are A₁′(v₁), A₂″(v₂), E′ (v₃) and E′(v₄). The corresponding four modes in C_3v geometry are A₁(v₁), A₁(v₂), E(v₃) and E(v₄) respectively,

c) Re is considered as S & DITHIONE CONSIDERED AS H

x2, y de h Be orbitals h " 22" dhilena orbitals

d) compound wii be stable