Figure 8.

IR and Raman spectra of TS-1 provide information on the local structure of the Ti(IV) sites and on their adsorbate-induced flexibility. (a and b) IR and Raman spectra, respectively, of pure silicalite (dotted) and TS-1 (full) dehydrated in vacuum at 400 °C. Spectra reproduced with permission from ref (146). Copyright 2006 John Wiley and Sons. (c) Background-subtracted IR spectra of TS-1 activated in vacuum at 400 °C upon increasing coverages of CD₃CN in the ν(C≡N) region (maximum coverage in blue). (d) The same as in (c) in the spectral region characteristic for the zeolite framework modes. Spectra reproduced with permission from ref (147). Copyright 2003 American Chemical Society. (e) Schematic representation of the effect of the adsorption of acetonitrile on the coordination geometry of the Ti(IV) sites in TS-1. (f) Evolution of the IR spectra of TS-1 activated in vacuum at 400 °C upon increasing the coverage of H₂O (from black to blue). (g) Raman spectra of TS-1 activated in vacuum at 400 °C before (black) and after (blue) interaction with H₂O. Spectra reproduced with permission from ref (148). Copyright 2002 American Chemical Society.