Schematic of the σ transition metal complexation(16-19) of H2 to CuF. The center shows the interactions while the pictures
are renderings of the calculated molecular orbitals for the individual monomers and the complex. Only the most important
orbitals and interactions involved in the bonding are shown. The HOMO of H2, f, interacts with the LUMO of the CuF, a,
forming the forward-bonding interaction, orbital b. The shape of orbital b is influenced by the HOMO of CuF which is not
shown. The LUMO of H2, c, is capable of overlap with lower level π-type orbitals, d, from CuF providing the backbonding
(shown in e) and should result in the elongation of the H2 bond.
Daniel J. Frohman; G. S. Grubbs II; Zhenhong Yu; Stewart E. Novick; Inorg. Chem. 2013 DOI: 10.1021/ic301941k