AV501 is back in service!

At long last, we are able to put the AV501 back in service. Here is a rundown of what’s new:

New Location!

We moved the spectrometer next to the AV400 in B-73. It’s previous location had vibration issues from chilled water lines in the sub-basement that were suspended from the ceiling almost directly below the magnet. We can’t be sure if those contributed to the quench, but we were not going to take any chances. Please use the same table as for the AV400 to prepare and sort samples.

New Experiment Names

We reworked the experiment list to move away from virtual parameter sets, which didn’t always play nice with IconWeb. I renamed some of the experiments and changed the experiment descriptions in the hope that it will be more user friendly. If these work out, I will make the same changes on the other instruments as well.

New Experiments!

While we were waiting for the magnet to stabilize we set up:

1. 1H tlc experiment optimized for improved sensitivity at the expense of greater errors in integral values. We estimate that you should be able to get ¹H spectra on samples extracted from analytical TLC spots. Please try it and let us know if it worked for you.
2. Packaged H/C and 2D experiments that adjust the spectral widths in 2D spectra based on the 1D results.
3. TOCSY (5 min). This experiment connects all protons within a coupled network, and is most useful for leveraging a few well-resolved signals to deconvolute overlapped regions.
4. NOESY (20 min), which can connects protons through space and is one of the primary NMR experiments for determining regio- and stereochemistry.
5. 2D HMBC experiments for the indirect detection of ¹⁵N, ²⁹Si, and ³¹P.
   1. ¹⁵N takes 20 minutes and requires 10-20 mg of materials.
   2. ²⁹Si takes 5 minutes and is much more sensitive than direct or even INEPT detection of ²⁹Si, and—unlike INEPT—it does not need to be optimized based on the silicone-containing functional group.
   3. ³¹P also takes 5 minutes and can be very useful for identifying which observed coupling in the ¹H spectrum comes from phosphorus.

Missing Experiments

We have not set up any nuclei other than ¹H, ²H, ¹³C, ¹⁵N, ²⁹Si and ³¹P. If you are missing a nucleus, bring us a sample and we’ll set it up.

Thank you!

I want to thank all of you again for your patience. I know it’s been rough, but we got through it with minimal conflict, which is a testament to your kindness and civility.
While we tested the spectrometer and experiments as much as we could, there may still be issues to work out for some samples and solvents. If you have any issues at all, please let us know so we can address it promptly.