Universität Erlangen-Nürnberg, Institut für Organische Chemie

NMR Department

Genral Guidelines for Spectrometer Users

Page under construction for guidelines for new Bruker machines

We have 5 spectrometers available in the NMR department; for specifications, see homepage of the NMR department.

The two 60 MHz machines (PMX60) run in CW mode and are purposed for measurement of 1H spectra only. They are accessible to any Diploma-, PhD-student, postdoc, and - in special cases - students of the practica. You will be given a training course, please contact the NMR crew. Though 60 MHz machines may seem outdated, they are still the fastest way to run a quick overview spectrum, e.g. to check out whether a sample from distillation is solvent free, to check out if an unwanted isomer has disappeared etc. etc. Shimming is very easy on these machines, and you will obtain a spectrum within a few minutes.

The EX400 is equipped with a sample changer and runs day and night. The sample changer is charged by our service personnel, so under normal conditions this machine is purely service driven.

The GX400 is both a service machine and a device for access of individual users. This machine has facilities for proton and carbon spectra, as well as for all nuclei from 15N to 31P. There is a variety of probeheads (see homepage for specifications). This machine is also the standard device for variable temperature (VT) spectra. VT operation is easy on this machine. In addition, and in contrast to most spectrometers of other manufacturers, low temperature measurements can be run unattended. In case that the dewar should run out of liquid nitrogen, the measurement is interrupted automatically, data are saved up to the time of LN2 failure. Each user has an account of his own which is password protected (will be made available by Dr. Bauer).

All service spectra measured on the GX400 will be regularly backuped, so normally there is no data loss. However, it is recommended to users to do an additional backup of their own data. Trained users of the GX400 may login from outside and do data transfer by usual ftp.

Processing of GX400 data can be done on the machine directly. However, depending on taste, users can also do offline processing, e.g. on a PC by using the NUTS NMR software. Look up the postprocess page for further details.

The Alpha500 spectrometer is employed for all kinds of special measurements which can't be done on the EX400 or the GX400. For example, the Alpha is equipped with solid state facilities (MAS). Solid state spectra can be taken for all nuclei from 15N to 31P. Naturally, 13C is the most frequently measured nucleus. This spectrometer also has facilities for field gradient techniques and inverse detection methods; there is a special inverse probehead (inner coil for 1H, outer coil for heteronuclei). Furthermore, the Alpha has facilities for 19F measurements. In addition, it's possible to run spectra of heteronuclei (e.g. 13C) under 19F decoupling. However, these types of measurements require severe rebuilding of the spectrometer (ca. 1h) prior to the measurements. Simultaneous proton and fluorine decoupling is not possible.

Users are asked to treat the spectrometers as careful as possible. Keep in mind that a high field spectrometer is a very sophisticated machine. At least a basic knowledge of the principles of NMR is mandatory for proper operation. In case of doubt or problems please don't hesitate to ask the operators. A quick question which can be answered within seconds is much more convenient than, e.g., a broken probehead. Your questions are always welcome, don't hesitate to bother us.

Back to NMR Department Home Page

Updated March 2, 1999

NMR Department
Institute of Organic Chemistry
Location: Rooms U34, U35, U36
University of Erlangen-Nürnberg
Henkestrasse 42
D-91054 Erlangen, Germany
Phone +49-9131-85-22987
FAX +49-9131-85-22991
e-mail: bauer@organik.uni-erlangen.de