Chemical Shift (Delta)
Definition
The position of an NMR signal on the frequency axis, expressed in parts per million (ppm) relative to a reference (TMS = 0). It reports the electronic environment of the nucleus, with shielded nuclei at low ppm and deshielded nuclei at high ppm.
Related terms
- DEPT 135
- A 13C editing experiment that flips CH3 and CH peaks up, CH2 peaks down, and makes quaternary carbons disappear. Used to assign...
- Deuterated Solvent
- A solvent with most or all of its protons replaced by deuterium (CDCl3, DMSO-d6, D2O), used so the solvent itself is invisible...
- FID and Fourier Transform
- The free induction decay is the time-domain signal emitted by relaxing nuclei after the RF pulse. A Fourier transform converts the FID...
- Integration
- The third stage, in which laundered funds re-enter the legitimate economy as apparently clean wealth. Common integration mechanisms include real estate purchases,...
- Spin-Spin Coupling (J)
- Splitting of an NMR signal into a multiplet by adjacent magnetic nuclei. The n+1 rule predicts the number of lines for first-order...
Explained in
- Nuclear Magnetic Resonance (NMR) SpectroscopyThe position of an NMR signal on the frequency axis, expressed in parts per million (ppm) relative to a reference (TMS = 0). It reports the electronic environm...