While C=C distance information can be derived via IR spectroscopy, Figure shows that the NMR parameters σiso, σ11, and σ22 are nonlinear with geometric changes and that DFT and NLMO calculations may be paired to give a more detailed description of geometric changes that occur in ethylene upon binding. We measured C solid-state NMR spectra of three MOFs with coordinatively unsaturated Cu(I) sites (Figure ). Upon dosing with ethylene, we measured a static Briefly, Cu(I)-MFU-4l was prepared following literature procedures, with ~85 % of the peripheral chloride anions exchanged for formate anions, as quantified through 1 H NMR spectroscopy following dissolution in d6-DMSO/D2SO4. Thermolysis at 180 ºC for 1 h under vacuum afforded a mixture of Cl -/HCOO - anions at the Zn sites, whereas further thermolysis at 230 ºC for 3 h afforded formate decomposition to yield a mixture of Cl -/H -anions at the Zn sites.