Solid-State 29Si NMR and Infrared Studies of the Reactions of Mono- and Polyfunctional Silanes with Zeolite Surfaces

• Main Authors: Bein, Thomas, Carver, Robert F, Farlee, Rodney D, Stucky, Galen D
• Format: Report
• Language: English
• Subjects: ALKYL RADICALS; BRIDGES; HIGH TEMPERATURE; HYDROXYL RADICALS; INFRARED RADIATION; Organic Chemistry; PATTERNS; Physical Chemistry; PROTONS; REACTANTS(CHEMISTRY); RESPONSE; SILANES; SILOXANES; SPECTROSCOPY; SUBSTITUTES; SURFACES

The combined use of 29Si magic-angle spinning NMR spectroscopy and in situ infrared techniques allows for the first time the determination of the intrazeolitic reaction products and details of the interaction of various silanes with zeolitic protons. Alkoxy groups at Me3SiOMe and MeSi(OMe)3 are readily lost to form hydroxy groups and then siloxane bridges to the zeolite framework. At elevated temperatures, alkyl groups are also split off from the silane, and more highly substituted siloxane species are generated which are anchored to the framework via two siloxane bridges. Chloro groups are rapidly hydrolyzed by the surface hydroxy groups, and the resulting products follow the reaction pattern of the alkoxysilanes. Prepared in cooperation with New Mexico Univ., Albuquerque, Dept. of Chemistry and E. I. du Pont de Nemours and Co., Wilmington, DE.