Figure 5.

In situ infrared spectra and ²H static NMR spectra

(A) Difference IR spectra showing the adsorbed CO₂ (orange) and C₂H₂ (pink) upon loading at 298 K and 1 bar adsorbate pressure into NbOFFIVE-3-Cu and subsequent evacuation of the gas phase within 3 s, respectively. Each is referenced to the spectrum of activated HUMs. Top inset shows the ν_as(CO₂) band and the bottom inset shows the decay of ν_as(C₂H₂) bands under vacuum. Notation and acronym: ν, stretching; δ, deformation; ip, in plane.

(B) Experimental ²H static NMR spectra of C₂D₂ adsorbed in NbOFFIVE-3-Cu (at a loading level of 0.4 C₂D₂ per Cu) as a function of temperature (blue lines) and simulated ²H spectrum of static C₂D₂ (red line).