Is Nitroglycerine a Nitro Compound or an Ester? I looked up nitroglycerine in a science dictionary (Oxford Dictionary of Science, 2003), and it explicitly mentions that nitroglycerine is an ester and not a nitro compound.

However my teacher told us in class, that nitroglycerine is a nitro compound (She didn't say it wasn't an ester though …). 

The definition for a nitro compound (courtesy Wikipedia) is:


  Nitro compounds are organic compounds that contain one or more nitro functional groups ($\ce{−NO2}$).


Assuming that definition is correct, as well and looking at the structure of nitroglycerine, it appears (to me) that nitroglycerine is both an ester and a nitro compound.

So who's right here?
The Oxford dictionary is correct.

A nitro compound is defined by the $\ce{-NO2}$ functional group, but only if that group is attached to a carbon atom. Once an additional oxygen is added, the molecule is basically inorganic nitrate and thus belongs to a wildly different compound class.

You think that is confusing? Well, an alcohol is defined by a hydroxy group — but only if that hydroxy group is attached to a carbon, which in turn is not attached to a different oxygen, nitrogen or sulphur atom, and which is not part of an aromatic system. Even more constraints in there.