Abstract
The oxygen functionality in low-rank coals can be converted into their fluoride equivalents by treatment of the coal with diethylaminosulfur trifluoride (DAST). The generated fluoride functional groups are identified by solid-state 19 F MAS NMR spectroscopy. The presence and nature of oxygen functionality is inferred from these species. Resolution in the 19 F chemical shift dimension of solid-state 19 F NMR spectra of DAST-treated coals is sufficient to allow the differentiation of primary and secondary fluorides and to distinguish aromatic and aliphatic carboxylic acid fluorides. By virtue of high 19 F nuclear sensitivity and isotopic abundance, 19 F MAS NMR permits the detection of functional groups at part per thousand level. This work reports the first clear evidence for the presence of low concentrations of primary and secondary alcohols in lignite, and for the separate identification of aliphatic and aromatic carboxylic acid functions in this coal.
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 callDisclaimer: 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.
