Hi all,
A follow up to my request in January for a copy of the table indicating frequency ranges for the various tuning sticks for Varian's old low-gamma 10mm probe (thanks to Paul from Varian for digging it up).
I have successfully observed K39 (23 MHz), Ag107 (20 MHz), and Ag109 (23 MHz) but have been unsuccessful observing Fe57 (16 MHz). I am far out of my element here with inorganic nmr but feel I have addressed all of my hardware concerns about the feasibility of this project (thanks to Rolf at Varian for the discussion about 1/4wave cables).
I am to a point where I believe the sample I am using as a test, before trying a labeled biological sample, is to blame for my lack of signal. I am using nearly neat Fe(CO)5 with a small amount of CDCl3. It is a natural abundance sample, but being in a 10mm tube and nearly neat I expected to see something. I am not sure what to expect in terms of T1 with this sample but have tried different d1's from 5-500 seconds with no success after 15+ hours of acquisition.
Anyone out there with some experience with such things able to provide some insight? Parameters, another Fe(II) compound, anything.
Thank you in advance,
David Richardson, Ph.D.
NMR Instrumentation Specialist
University of Central Florida
Department of Chemistry
PO Box 162366
Orlando, FL 32816-2366
david.richardson_at_ucf.edu<mailto:david.richardson_at_ucf.edu>
office: PS236 (407) 823-2961<tel:%28407%29%20823-2961>
lab: CH335 (407) 882-0117<tel:%28407%29%20882-0117>, PS151 (407) 823-2906<tel:%28407%29%20823-2906>
fax: (407) 823-2252<tel:%28407%29%20823-2252>
Received on Mon Apr 02 2012 - 04:58:37 MST