Effect of ligand-enhanced polarizability on vibration–field coupling strength

Determine whether the increased polarizability of the formamidinate complexes Mo₂(DAniF)₄ and Mo₂(DTolF)₄ affects only their Raman-scattering intensity or also increases the coupling strength between the Mo–Mo stretching coordinate and the locally confined Stokes Raman field.

Background

The paper compares three quadruply bonded dimolybdenum complexes with different supporting ligands. The formamidinate complexes Mo₂(DAniF)₄ and Mo₂(DTolF)₄ display substantially stronger and more structured Raman responses than Mo₂(O₂CCH₃)₄, which the authors associate with the greater electronic deformability and polarizability of the Mo₂ core induced by the formamidinate ligands.

Although enhanced polarizability clearly increases the visibility and intensity of the Mo–Mo-centered Raman features, the reported spectra alone do not determine whether it also strengthens the underlying coherent vibration–field interaction. Resolving this issue would distinguish a purely spectroscopic-intensity effect from a genuine ligand-controlled change in the vibration–field coupling strength.

References

It may also strengthen the coherent coupling of the vibrational coordinate with the local scattering field, although the spectra considered here do not by themselves establish whether the increased polarizability affects only the Raman intensity or also the coupling strength.

— Strong Coupling of the Mo Mo Stretching Mode to a Locally Confined Stokes Raman Field in Mo2 Molecular Resonators  (2608.26482 - Meng et al., 27 Aug 2026) in Results, paragraph beginning “The contrast among 1, 2, and 2′ is notable”