Question: What are NMRs?

Helen Pritchard-Smith answered on 25 Jun 2013:

Nuclear magnetic resonance imaging, i make up a sample of a product, something i am interested in but i am not certain of what it is. I put it in a thin tube and place it in an NMR machine rack – robots tend to put the sample in the machine. It gets lowered into the machine which consists of a cooled magnet. All of the atoms start spinning because they are surrounded by a big magnets (a bit like spinning tops that you play with as a child). Then you fire pulses of energy (specifically electromagnetic radiation) and this excites the atoms to a higher energy state.

When the atoms relax back to a lower energy state they release the energy you gave them in the pulse and it is this energy that is measured. Each atom releases specific amounts of energy depending on what element it is and what it is connected to i.e. carbon or hydrogen. This information is used to make a spectrum or graph that gives me detailed information about what i have made and therefore whether my reaction has been successful.

Hope this is clear!