Figure 6.

IR spectroscopy reveals that the adsorbate-induced structural rearrangements of the Cr(II) sites at the silica surface is a function of the adsorbate. The figure shows the evolution of the IR spectra of Cr(II)/SiO₂ interacting with CO at room temperature (bold gray spectra) after contact with a second, stronger, ligand: (a) ethylene, (b) cyclohexene, and (c) NO. All the spectra are reported after subtraction of that collected prior interaction with any probe and in the ν(CO) region. (a) Reproduced with permission from ref (59). Copyright 2005 American Chemical Society. (b) Reproduced with permission from ref (127). Copyright 2016 American Chemical Society. (c) Reproduced with permission from ref (128). Copyright 2010 John Wiley and Sons.