Problem Set 3

and [½, ½, ½] in the coordinate system with fourfold quantization, what are their positions in
the coordinate system with threefold quantization
b. Use the real d‐orbital functions to find basis sets for the t 2 and e representations of the T d point
group in the coordinate system with trigonal quantization.
3. In 1993, Wilkinson and Hursthouse reported
(Polyhedron, 1993, 12, 2009‐2012) the preparation
and X‐ray crystal structure of Ir(O)(mes)3 (mes =
mesityl, 2,4,6‐trimethylphenyl). The structure of the
complex is shown to the right.
a. Construct an MO diagram for C 3v Ir(O)(mes) 3
using the following orbitals: five metal 5d orbitals, one set of three ligand σ orbitals, and the oxo
2pσ + two 2pπ orbitals.
b. Extend your diagram to illustrate the correlation between the trigonally quantized ML 4 orbitals
and the MOs of Ir(O)(mes) 3 .
c. Is there a unique set of d‐orbitals in C 3v symmetry that forms a basis for the e irreducible
representation If so, what is that set of d‐orbitals If not, what is the implication for the
molecular orbitals of e symmetry in Ir(O)(mes) 3
d. Using your MO diagram, fill in the d electrons and predict the ground‐state electronic
configuration. With this prediction, is the metal‐oxo bond order shown above correct Why or
why not Do you think that a complex of the form [Ir(O)(mes) 3 ] 2− could exist Why or why not
e. Does Ir(O)(mes) 3 represent a breach of the oxo wall Why or why not