Hydrogen Environments In Low-OH, F, Cl Apatites Revealed By Double Resonance Solid-State NMR

作者：Vaughn John S; Woerner William R; Lindsley Donald H; Nekvasil Hanna; Hughes John M; Phillips Brian L^*

来源：Journal of Physical Chemistry C, 2015, 119(51): 28605-28613.

DOI：10.1021/acs.jpcc.5b10561

A series of hexagonal low-OH, F, Cl apatite compositions synthesized by high-temperature reaction is characterized by powder X-ray diffraction (PXRD) and H-1 magic-angle spinning (MAS) solid-state NMR methods. Quantitative H-1 NMR analysis indicates that the hydroxyl content in all samples is low, less than 2 mol percent, and is due to OH in apatite. H-1{P-31} rotational echo double resonance (REDOR) NMR difference spectroscopy indicates that hydroxyl groups are preferentially oriented toward fluorine, probably because of OH-center dot center dot center dot F- hydrogen bonding. Clustered hydroxyl groups are also observed and may play a significant role in hexagonal solid solution for ternary F, OH, Cl apatites.

• 出版日期2015-12-24