# Nuclear Magnetic Resonance Spectroscopy

## Vocabulary

### 1H nuclear magnetic resonance spectrum

plot that has the radio frequency on the $x$-axis and the signal or amount of energy on the $y$-axis

### 3-D nuclear magnetic resonance

spectrum that plots the signals from three different nuclei against one another in three-dimensional space

### alpha state

energy state that is parallel to a field and requires lower energy

### beta state

energy state that is antiparallel to a field and requires higher energy

### chemical shift

difference in the resonant frequency of two protons because of their environment

### correlation spectroscopy

plot where both axes are from proton NMR and they are plotted against one another to show which protons are coupled to each other

### deshielded

characteristic of protons near highly electronegative nuclei in which the protons experience more of the magnetic field

### deuterated

characteristic of a compound in which a hydrogen atom is replaced with a deuterium atom that has one proton and one neutron as compared to hydrogen that does not have any neutrons

### deuterated solvent

liquid that is used to dissolve other substances (a solvent) that has at least one of its hydrogen atoms replaced with a deuterium atom that has one proton and one neutron as compared to hydrogen that does not have any neutrons

### deuterium

isotope of hydrogen that contains one proton and one neutron

### diastereotopic

characteristic of hydrogen atoms that are not in the same chemical environment and produce different signals in NMR spectroscopy

### distortionless enhancement of polarization transfer C-NMR

technique that provides the number of protons bonded to each carbon as well as the chemical shift provided by a regular carbon nuclear magnetic resonance (13C NMR)

### downfield

left part of the NMR spectra where a low field strength is applied

### enantiotopic

characteristic of hydrogen atoms that are not in the same chemical environment and produce different signals in a chiral environment, such as in chiral solvents in NMR spectroscopy

### heteronuclear correlation spectroscopy

1H NMR spectra plotted on one axis with 13C spectra plotted on the other axis

### homotopic

characteristic of hydrogen atoms that are in the same chemical environment and produce the same signal in NMR spectroscopy

### integration

intensity of the signal on a proton nuclear magnetic resonance (1H NMR) spectrum, providing a ratio of the number of protons found in the signal

### nuclear magnetic resonance

resonance that occurs when atomic nuclei that have spin are placed into a magnetic field. Individual spins that are normally random in orientation line up parallel to the magnetic field.

### nuclear magnetic resonance spectrometer

instrument that uses the magnetic moment to gain information about the structure of a compound

### nuclear spin

magnetic moment resulting from the total angular momentum of certain nuclei, such as those with an odd number of either protons or neutrons

### nucleon

proton or neutron in an atomic nucleus

### shielded

characteristic of protons that not experience the full effect of the magnetic field because of the electrons surrounding them

### split

characteristic of a signal that has multiple peaks of different areas and heights

### upfield

right part of the NMR spectra where a high field strength is applied