Volume 92 Issue 12 , Pages 2803 – 3134 (December 2009)
Xianyu Xue, Masami Kanzaki
Published Online: Nov 23 2009 6:54PM
Solid-state 1H nuclear magnetic resonance (NMR) spectroscopy has developed into a versatile, high-resolution method for elucidating the detailed structures of both crystalline and amorphous materials. Here, we summarize our recent endeavors in applying this method to crystalline and glassy silicates and related inorganic materials. We first present updated correlations between 1H chemical shift and O⋯O and H⋯O distances of O-H⋯O hydrogen bonds, derived from a comprehensive 1H chemical shift database containing both original high-quality fast magic angle spinning (MAS) and two-dimensional combined rotation and multiple pulse spectroscopy (CRAMPS)-MAS NMR data and literature MAS NMR data for a large number of inorganic compounds, including phosphates, silicates, (oxy)hydroxides, borates, sulfates, and carbonates. These correlations may be used to estimate hydrogen-bonding distances for inorganic oxide materials of unknown structures. We then present case studies for the application of high-resolution two-dimensional 1H CRAMPS-MAS NMR to unravel the order/disorder of proton distributions in crystalline high-pressure hydrous silicates. Finally, we summarize some of our results on the water speciation in hydrous (alumino)silicate glasses of a range of compositions obtained through comprehensive 1H MAS NMR, and 29Si-1H and 27Al-1H double-resonance NMR experiments, and analyze them in the framework of a quasi-chemical model.