求助偏共振去耦谱的原理

Off-Resonance Proton-Decoupled 13C Spectra
In order to retain the information about the attached hydrogens that a proton-coupled spectrum provides, a compromise technique called off-resonance proton-decoupling is used.

In this technique, the sample is swept by a radio frequency generator which is either slightly upfield or downfield of normal proton resonances (i.e., off resonance). When off-resonance decoupling is used, the apparent coupling constant is greatly reduced, and peak overlap is minimized.

In point of fact, off-resonance proton-decoupled spectra often show only singlets for each carbon atom, but the multiplicity of the peak (the number of protons directly attached) is reported as a letter designation above the peak (s (singlet), d (doublet), t (triplet), or q (quartet)).