NMR: Difference between revisions
From Pumping Station One
| Line 54: | Line 54: | ||
Like many types of spectroscopy, NMR ultimately produces a squiggly line on a graph.<br> | Like many types of spectroscopy, NMR ultimately produces a squiggly line on a graph.<br> | ||
Breaking down the acronym, we have: | Breaking down the acronym, we have: | ||
* '''Nuclear''' simply means we are concerned with the nucleus of the atoms we are interested in (so the protons and neutrons) | * '''Nuclear''' simply means we are concerned with the nucleus of the atoms we are interested in (so the protons and neutrons). In spite of sounding scary, ionizing radiation is not involved in this technique (which is the actually scary part when you hear the world nuclear). | ||
* In essence, any atoms that have an odd number of protons or neutrons (or both) will behave like '''magnets'''. This is due to their '[https://en.wikipedia.org/wiki/Spin_(physics) spin]'. Only some isotopes of some elements have this property. These are commonly referred to as "NMR active" (Common ones being Hydrogen-1 and Carbon-13). | * In essence, any atoms that have an odd number of protons or neutrons (or both) in their nucleus will behave like '''magnets'''. This is due to their '[https://en.wikipedia.org/wiki/Spin_(physics) spin]'. Only some isotopes of some elements have this property. These are commonly referred to as "NMR active" (Common ones being Hydrogen-1 and Carbon-13). | ||
* By exposing atoms to a magnetic field and RF of a given frequency, we can put them into '''resonance'''. This can be measured, and is the basis for the technique. | * By exposing atoms to a magnetic field and RF of a given frequency, we can put them into '''resonance'''. This can be measured, and is the basis for the technique. | ||
While the nucleus plays a central role in this technique working at all, the configuration of the electrons of an atom in relation to other atoms does play a subtle but very important role in NMR -- [https://www.youtube.com/watch?v=TJhVotrZt9I an atom's configuration of electrons does influence how much an atom is diamagnetically shielded from the effects of RF.]. We use this to our advantage because different electron configurations will resonate at slightly different frequencies. | While the nucleus plays a central role in this technique working at all, the configuration of the electrons of an atom in relation to other atoms does play a subtle but very important role in NMR -- [https://www.youtube.com/watch?v=TJhVotrZt9I an atom's configuration of electrons does influence how much an atom is diamagnetically shielded from the effects of RF.]. We use this to our advantage because different electron configurations will resonate at slightly different frequencies. This allows us to discern between different ways a nucleus can exist within a sample. | ||
So, in essence, with NMR: | So, in essence, with NMR: | ||
