Wednesday, 26 March 2008

13C Chemical Shift prediction: Typos and NMR misinterpretations

It is well known that 13C Chemical Shifts are essential for structure verification and elucidation of organic molecules by NMR. For example, in the field of structure verification, one can compare the observed 13C chemical shifts with the calculated (predicted) values in such a way that the structure hypotheses can be assessed by means on some numerical matching factor.
What is less evident is the great potential that 13C chemical shift prediction has in order to reveal typos and misinterpretations of NMR data that often (much more than expected, I’m afraid) appear in the experimental sections of scientific literature.

Wolfgan Robien has recently created a very interesting Web page in which he shows how his famous CSEARCH program for 13C –NMR prediction can be used for automatic data-checking. According to his personal opinion, there are at least 3 scenarios in which such checks should be done:

  • Daily routine during generation and interpretation of NMR-data
  • Check again during preparation of a manuscript
  • Check again during the peer-reviewing process ('robot-referee')

Mnova is honoured to include Wolfgang Robien’s CSEARCH algorithm within its NMRPredict Desktop plugin and includes simple yet very useful verification tools which can be used to easily identify errors in 13C-NMR data assignments.

Basic Misinterpretations, Typos and other Sad Events in NMR-Spectroscopy

1 comment:

Wolfgang Robien said...

There are already 10 examples online - I promise: More to come!

On this webpage only examples with a difference of AT LEAST 15 to 20ppm between experimental and predicted chemical shift values are shown.