Summary of the first section
Alright, time for a break - you've earned it!
- The number
of signals in the 1H-NMR
spectrum of a molecule is equal to the number of
- Protons are
stereo-equivalent, if they form similar bonds,
i.e., if the geometry with respect to the remainder
of the molecule is identical, and if the character of the neighboring
bonds is identical.
- The identification
of equivalent protons in a molecule can be achieved by two
different methods. Either you can use each proton
in turn as a reference point and characterize the remainder of the
molecule based on it to find protons with identical environments. Or
you can look for symmetry operations that relate
different protons to each other.
- In non-rigid molecules the protons of a methyl or methylene group give rise
to a single, shared signal.
The next section will deal
with chemical shifts.