|Science & Fun | Home | Introduction into the 1H NMR Spectroscopy|
Number of signals and symmetry in flexible systemsRule:
In general you will observe this behaviour if you have CH2 groups and at least one asymmetric carbon atom together in one molecule.
Example: Within the compound
with one asymmetric carbon atom (C*) it is impossible to fit the conformations:
with any symmetry operation. Each moment of the free rotation there interact different chemical environments with both methylene protons H(1) und H(2). Both methylene protons show their individual signal, as demonstrated within the experimental spectrum.
And now back to more fundamental problems