Nuclear magnetic resonance (NMR) spectroscopy

There are two distinct braches to the NMR provision for researchers in the Department of Chemistry: walk-up service and staff-run service.

Walk-up service is provided on four robot spectrometers - a wide range of basic experiments are available, with the restriction that daytime experiments are limited to a maximum of 15 minutes per spectrum and overnight/weekend acquisitions may not exceed three hours per spectrum. There is a request service for longer or more complex experiments, the spectra for which are recorded by NMR Staff.

Walk-up service

• B400 Bruker Avance III 400 MHz room B.12, runs 24/7

Proton, Carbon, Dept, Cosy, Hsqc, Hmbc, 31P, 19F, Noesy
Individual groups also have additional experiments enabled, which are group specific.

• B300 Bruker Avance 300 MHz room B11, runs 24/7

Proton, Carbon, Dept, Cosy, Hsqc, Hmbc

• B500 Bruker Avance II+ 500 MHz, room B11, 10am Monday to 10am Wednesday

Proton, Carbon, Dept, Cosy, Hsqc, Hmbc

• B200 Bruker Avance 200 MHz, 2nd floor teaching, out of term time

Proton, 31P

Staff-run service

• Proton, Carbon, Dept, Cosy, Hsqc, Hmbc, 31P, 7Li , 11B,other heteronuclei, Noesy, Roesy, Tocsy
• 1D Noesy(nOe), water suppression including 2D expts
• Variable temperature, standard range 120°C to -40°C, depending on solvent
• Time course studies

Below is a list of NMR spectrometers available in the Department of Chemistry:

• Bruker Avance 300 MHz spectrometer

This refurbished instrument is equipped with a new gradient shimming facility and data system. It has a 60 position autosampler and a dual direct observation probe, which is optimised for 13C observation experiments. It is used as a 24/7 walk-up facility and supports 1D proton and carbon experiments together with a wide range of proton homo-nuclear, 2D and hetero-nuclear proton-carbon correlation 2D experiments.

• Bruker Avance 200MHz spectrometer

This instrument has been refurbished, including a new data system and new 60 position autosampler. It has a proton and X-channel tuneable probe, but does not have auto-tune for online nucleus selection. It is used, first line, to support undergraduate projects, but will be available for walk-up use by researchers and postgraduates outside of the periods that are needed for undergraduate use. The main function will be for quick turnaround proton spectra for reaction monitoring. 31P spectra can also be recorded under automation.

• Varian Inova 300 MHz spectrometer

This is an older instrument with a 50 position autosampler and a dual proton/carbon probe. It is configured for 24/7 walk-up use. It supports a range of 1D and 2D experiments, which are broadly similar to those available on the Bruker Avance 300MHz instrument. It does have gradient shimming and gradient assisted 2D experiments. Generally now used only as a backup.

• Bruker Avance III new 400MHz spectrometer

This new spectrometer is configured mainly for NMR staff to use for our NMR service for longer or more complex experiments. Users access the facility via filling in a request in the usual electronic/paper request form. It has a versatile auto-tune probe, which will tune to variety of nuclei. Pulsed field gradient enhanced 2D experiments, as well as the usual proton and carbon spectra, will be performed. Variable temperature and time course experiments are also catered for.

• Varian VMS and Bruker Avance II+ 500 MHz spectrometers

These units will support mainly research use, but NMR staff will be able to reserve time on either for running experiments that require higher field, sensitivity or probe requirements than is available on the Avance 400 model. Both these spectrometers are fully equipped for automatic operation with 50(Varian) and 60 (Bruker) autosamplers fitted. Currently the Bruker instrument is available for walk-up use on two days each week as a minimum. Sometimes weekends are also available for walk-up users.

• Varian Inova 400MHZ and 300 MHz spectrometers

These two older manually operated spectrometers will continue to be supported for the time being. They will be used as bookable units for both users and NMR staff. A wide range of experiments may be performed, particularly on the 400MHz model. The 300 MHz model is rather more basic and lacks pulsed field gradients.