The first part of this question is a gentle introduction to the
drawing of isomers. Structural isomers are those which involve
different arrangements of the carbon skeleton, and different
placements of the functional groups. It should be noted that cis
and trans isomers are classed as geometric isomers, and so are not
The next part of the question is deliberately open ended. We have
been able to find just over 30 different structures (maybe you can
find more?), although it is important to note that many of these
structures would be too unstable to be formed in the lab. However,
this question is an exercise in logical structural drawing, rather
than a detailed analysis of chemical stability.
The IR spectrum has three clear peaks:
~3100 cm$^-1$ broad peak correspond to -OH
~3300 cm$^-1$ corresponds to -NH
~1700 cm$^-1$ corresponds to C$=$O, rather than C$=$C since the
absorption is SHARP.
The important point to note is that the peak at 3300cm$^-1$ is only
single rather than a double absorption, which corresponds to an NH
but NOT NH$_2$.
The zoomed IR spectrum shows an absorption at ~1670cm$^-1$, which
indicates that the molecule contains an amide group. Thus because
of the single peak at 3300cm$^-1$, this is a secondary amide:
The NRM spectrum has 6 peaks, which shows that there are 6
different carbon environments. Since six of the eight carbon atoms
are present in a benzene ring, the location of the substituents
around the ring must be:
From all the data so far, seven possible structures are:
The m/z of 58 corresponds to $[C_2H_4NO]^+$.
The m/z of 93 corresponds to $[C_6H_5O]^+$.
The additional information that the molecule was constructed from
a nitro-aryl suggests that the nitrogen must be attached directly
to the benzene ring. The only structure of the three remaining
This molecule is paracetamol