19-Fluorine nuclear magnetic resonance chemical shift variability in trifluoroacetyl species

orine nuclear magnetic resonance chemical shift variability in trifluoroacetyl species Review (782) Total Article Views Authors: Sloop JC Published Date February 2013 Volume 2013:3 Pages 1 - 12 DOI: http://dx.doi.org/10.2147/ROC.S38495 Received: 05 December 2012 Accepted: 11 January 2013 Published: 20 February 2013 Joseph C Sloop School of Science and Technology, Georgia Gwinnett College, Lawrenceville, GA, USA Abstract: This review examines the variability of chemical shifts observed in 19-fluorine (19F) nuclear magnetic resonance spectra for the trifluoroacetyl (TFA) functional group. The range of 19F chemical shifts reported spectra for the TFA group varies generally from 85 to 67 ppm relative to CFCl3. The literature revealed several factors that impact chemical shifts of the TFA moiety - substrate topology, electronic environment, solvent polarity, and concentration effects. Often these effects conspire to cause deshielding of the TFA group by up to 15 ppm. These factors will be examined for a series of TFA-functionalized acyclic, cyclic, aromatic, and heterocyclic molecules.