Abstract
Resume Infrared spectra of irreversibly adsorbed species given by CF 3 CH 2 OH, CCl 3 CH 2 OH (D) and CCl 3 CHDOH on aluminas modified by addition of sodium or fluoride ions have been investigated in the 4000-1000 cm −1 range. They were compared to those obtained on pure alumina, in order to study the changes in acid—base properties. On sodium-treated aluminas, dissociative adsorption occurred; the wavenumbers of ν(CO) and ν(CH) vibrations of alcoholate species showed that the ionic character of COAl bonds increased with increasing sodium content up to 2.5% wt. It was deduced that Na + introduction enhanced the basicity of adsorption sites. Similar effects were obtained when pure alumina samples were irreversibly pretreated with pyridine. On fluorinated aluminas, the study of the 1500-1000 cm −1 range evidenced formation of both alcoholate and non-dissociatively adsorbed species. As the latter gave rise to high frequency ν(CH) vibrations, it was concluded they were coordinately adsorbed. Addition of fluoride ions therefore increased the Lewis acidity of alumina samples.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Spectrochimica Acta Part A: Molecular Spectroscopy
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
