HomeFacility InfoNMR InstrumentationAV501

AV501

PLEASE READ this document carefully before using the AV501 for the first time!

If you have completed the Bruker automation training, you can use the AV501. If you are new to the facility, please look at the training options here.

The AV501 is located in room B-69 in S.T. Olin Laboratory and is best used for routine one- and two-dimensional spectra on dilute or complex samples. This is a 500 MHz spectrometer equipped with a liquid-nitrogen cooled cryoprobe, so its sensitivity is 2-3 times higher than the Varian INOVA-500 and 5-6 times higher than the AV400. It should be suitable for 1H spectra on very dilute samples with 0.1+ mg analyte and other nuclei on dilute ones (0.5+ mg). The AV501 is functionally the same as the AV500, except it cannot run 19F experiments due to a hardware limitation.

The AV501 joined the facility in the summer of 2021. The magnet was donated by Prof. Robert Oswald and the Cornell Vet School, and we bought the electronics console used with Cornell funds. We added a Prodigy BBO cryoprobe in the fall of 2021.

The main features of the instrument are:

  1. Bruker AVIII electronics console
  2. Prodigy BBO broadband cryoprobe.
  3. SampleXpress™ 60-position sample changer
  4. Fully automated operation
  5. IconWeb™ web-based user interface
  6. Sample temperature range: -40 to +150°C. Default temperature is 25°C (298K).

What can it do?

We have the following experiments set up for IconWeb:

  1. 1H experiments:
    • H1-quant: Quantitative 1H (4 scans, 90° excitation, 30 s relaxation delay)
      We recommend this experiment because it combines more-than-good-enough sensitivity on most samples with excellent quantitation across all hydrogen environments.
    • H1: Semi-quantitative 1H (16 scans, 45° excitation, 2 s relaxation delay)
      This experiment sacrifices quantitation (expect aromatic and vinylic hydrogens to integrate lower than they should) for a ~60% increase in sensitivity relative to the quantitative experiment. Since sensitivity is rarely an issue with a cryoprobe, this is not a trade-off we recommend for routine use.
    • H1-WET-1F: 1H with single frequency signal suppression. Used for acquiring spectra in non-deuterated solvents with a single resonance (CHCl3, CH2Cl2, etc.) or for samples in deuterated solvents that contain a single intense, unwanted signal.
    • H1-WET-2F: 1H with two frequency signal suppression. Used for acquiring spectra in non-deuterated solvents with a two resonances (THF, MeOH etc.) or for samples in deuterated solvents that contain two intense, unwanted signals.
    • WATERSUP: 1H in H2O/D2O mixtures. Will suppress the water signal but may also wipe out analyte signals close to the water chemical shift.
  2. 2D Experiments:
    • 2D gCOSY: 2D experiment that connects coupled protons. It’s very quick (4.5 minutes) and robust, and can help you trace networks of neighboring hydrogens. We highly recommend running one for every new compound.
    • 2D HSQC: 2D experiment that connects hydrogens with the carbons they are attached to. It’s more sensitive than a 1D carbon and provides multiplicity information like a DEPT135. It takes about 5 minutes and should work for most samples with 1+ mg analyte. Please note that you will not see quaternary carbons as well as a few others, like terminal alkynes. Ask us if you have questions.
    • 2D HMBC: 2D experiment that connects hydrogens with neighboring carbons. It’s more sensitive than a 1D carbon and will detect quaternary carbons if they are within three or possibly 4 bonds of a hydrogen. Try it out and we’ll help you with the analysis.
  3. 13C experiments:
    • 10 minute, non-quantitative 13C.
      NOTE: 10 minutes on the cryoprobe is equivalent to 60-90 minutes on a standard probe. Always try a 10-minute experiment before running a longer one.
    • 1 hour, non-quantitative 13C.
      If you need a longer experiment, increase the number of scans on the IconWeb “Add Experiment” page.
    • Quantitative 13C experiments.
      Use the “Cr” versions if you have a paramagnetic relaxation agent in your sample.
  4. 31P experiments:
    • 31P with 1H decoupling
    • 31P without 1H decoupling
  5. H2-lock-coup: 2H spectrum via the lock channel
  6. 19F experiments are NOT available
  7. 15N and 29Si are available but not added to users by default. If you need those experiments, let us know and we’ll add them to your drop-down list.
  8. If you would like to do other experiments and nuclei, please contact us!

You can access the AV501 IconWeb interface at https://av501.nmr.chem.cornell.edu (Requires Eduroam from campus and  VPN off campus)