I'd like to thank all those that took time to respond my question about
high-field 19F NMR. I received about 10 responses from people who do solution
19F NMR at 400-600 MHz (both for small molecules and for polymers as well as
biopolymers) and none of them (with one exception) have ever encountered any
problems due to CSA broadening. Only Richard Shoemaker (the exception) did
observe some broadening when he worked with inorganic complexes and
metalloporphyrins at 500 MHz. Nobody could remember any references pointing to
CSA broadening in high-field fluorine NMR in solution. Thank you once again.
Alex
Dr. Alex Kitaygorodskiy
Director NMR Facility
Clemson University
Clemson, SC 29634-1905
803-656-0611