16.12 : 异核单量子相关光谱 (HSQC)

Heteronuclear single-quantum correlation spectroscopy or HSQC is a sensitive 2D NMR technique that correlates heteronuclear spins coupled across a single bond.

A ¹H–¹³C HSQC spectrum correlates the proton chemical shift plotted on the horizontal F₂ axis to the carbon-13 chemical shift along the vertical F₁ axis.

HSQC spectra lack diagonal symmetry and each cross-peak indicates a proton attached to a carbon or a C–H bond.

In the spectrum of 2-chlorobutane, the carbon signal at 11 ppm from the shielded methyl group correlates to the proton multiplet at 1.01 ppm.

The carbon signal at 24.8 ppm arising from the deshielded methyl group is correlated to the proton multiplet at 1.52 ppm.

Similarly, the carbons appearing at 33.3 and 60.4 ppm are directly bonded to the protons that appear at 1.72 and 3.96 ppm, respectively.

HSQC techniques are used for the structural elucidation of complex organic molecules.