The Interaction of Guest Molecules with Co‐MOF‐74: A Vis/NIR and Raman Approach

Abstract Co‐MOF‐74 rod like crystals with a length of several hundred micrometers are synthesized by a solvothermal procedure and their interaction with different gases is evaluated for selective gas sensing. We show strongly anisotropic absorption behavior of the Co‐MOF‐74 crystals when illuminated with polarized light. The interactions of guests (CO 2 , propane, propene, Ar, MeOH, H 2 O) with Co‐MOF‐74, is studied by various spectroscopic techniques. Vis/NIR shows peak shifts of Co‐MOF‐74 depending on the interaction with the guest. In the visible and the NIR the maximum absorbance is shifted selectively corresponding to the intensity of the Co II –guest interaction. Even propene and propane could be distinguished at room temperature by their different interactions with Co‐MOF‐74. Raman spectroscopy was used to detect a modified vibrational behavior of Co‐MOF‐74 upon gas adsorption. We show that the adsorption of H 2 O leads to a characteristic shift of the peak maxima in the Raman spectra.