April 28, 2011
by Arvin Moser, Team Manager, Application Scientists, ACD/Labs
When the spectral data is sparse, the list of potential candidate structures can seem endless. The task then becomes sifting through the spectral data as a means to filter the candidates. The purpose of this puzzle is to perform such a task.
The following unknown compound with a mass of 380.1 +/- 0.5 Da comprises of the atoms C, H and O. There are 13 to17 carbon atoms expected, a minimum of 18 hydrogen atoms and a minimum of 1 oxygen atom. An expansion of the aromatic region of a 1H NMR spectrum is also provided. Given the following criteria, can the list of molecular formulae be dwindled down?
# MF Accurate Mass Mass Difference RDBE
1 C14H20O12 380.095476 -0.004524 5.0
2 C15H24O11 380.131862 0.031862 4.0
3 C16H28O10 380.168247 0.068247 3.0
4 C17H32O9 380.204633 0.104633 2.0
Obviously an aromatic compound (= 3DBE), considering also the small mass difference, i’d favor formula1.
… sorry: 4 DBE’s of course!