mer-trans-W(CO)3(PR3)2(η2-H2)

Questions for students are shown in red
The structure shown is the computational refinement
(DFT/LANL2DZ basis set) beginning with the results of a
X-ray crystal structure determination and a neutron diffraction study
published by Kubas et al in 1984.
A difference map of the two superimposed data sets
allowed the authors to locate the positions of the
hydrogens in the H2 ligand.


This is the vibration primarily associated
with what mode of the W(η2-H2) fragment?
And note that this vibration is "less pure fragment";
we are seeing more mixing with modes involving other atoms.

Original CCDC structure: CEJDEA
Kubas, G.J., Ryan, R.R., Swanson, B.I.,
Vergamini, P.J., Wasserman, H.J.;
J. Am. Chem. Soc., 106 1984, p. 451-452