Spin-spin coupling takes place between all NMR active nuclei, not just between protons. Here examples are shown of coupling to ¹³C, ²D, ³¹P, ¹⁹F and ²⁹Si are shown but many other nuclei can couple.

Coupling of ¹H to ¹³C

¹³C has a natural abundance just over 1% and the major isotope (¹²C) is not NMR active so very little of the proton signal is coupled. The coupled signal appears as small satellite signals either side of the main uncoupled signal (fig. 1). One bond coupling constants are between 115 and 250 Hz (usually 125 to 160 Hz).

Fig. 1. ¹H Signal of CHCl₃ showing ¹³C coupling

carbon satellite signals usually maintain the coupling pattern of the main peak (figs. 2, 3).

Fig. 2. Main signal of a ¹H AX₃ multiplet

Fig. 3. ¹³C satellites of a ¹H AX₃ multiplet

Sometimes the ¹³C breaks the symmetry of the molecule because its neighboring atom is ¹²C and the multiplet structure is changed in the carbon satellites. In the case of dioxane (below) the singlet (fig. 4) becomes a complex multiplet in the satellites (fig. 5).

Fig. 4. Main signal of dioxane is a singlet

Fig. 5. ¹³C satellites of dioxane

In the ¹³C spectrum the major splittings indicate the number of attached protons, a singlet for no protons an AX doublet for one (fig. 6), AX₂ for two and AX₃ for three (fig. 7). Additional smaller splittings are observed arising from long-range couplings.

Fig. 6. Aromatic region of ¹³C spectrum of ethylbenzene showing ¹H coupling

Fig. 7. Aliphatic region of ¹³C spectrum of ethylbenzene showing ¹H coupling

Coupling of ¹H and ¹³C to ²D

Coupling between proton and deuterium is most commonly seen in the solvent signals of the ¹H spectrum (fig. 8) and sometimes in the residual water signal that has become partially deuterated. (In the case of D₂O as a solvent, fast proton/deuteron exchange precludes the observation of ¹H-²D coupling in the water signal.) Deuterium is a spin-1 nucleus so its coupling forms 1:1:1 triplets for each coupled deuteron, 1:2:3:2:1 quintets for two coupled deuterons and 1:3:6:7:6:3:1 septets. ¹H-²D couplings are typically 1 to 2 Hz and ²D-¹³C couplings are typically 20 to 25 Hz.

Fig. 8. ¹H-²D and ¹³C-²D coupling patterns typical of solvent and residual water signals

Proton coupling can also be observed in the deuterium spectrum (fig. 9). As ¹H is a spin-½ nucleus, it couples to deuterium in the usual manner, forming a doublet for a single proton.

Fig. 9. ²D-NMR spectrum of CHDCl₂ showing a 1.1 Hz coupling of deuterium to proton

Coupling of ¹H to ³¹P

Long-range couplings to ³¹P (phosphorus) appear in the ¹H spectrum of phosphorus containing molecules (fig. 10). The couplings have effects over three to four bonds. The ³¹P spectrum also shows ¹H couplings (fig. 11). Couplings to phosphorus are also observed in the ¹³C spectrum (not shown here).

Fig. 10. ¹H spectrum of sphingomyelin showing the effects of ³¹P coupling

Fig. 11. ³¹P spectrum of sphingomyelin showing the effects of ¹H coupling

Coupling of ¹H and ¹³C to ¹⁹F

Fluorine couples strongly to proton up to three bonds away (fig. 12). This can bee seen as extra splittings in the ¹H spectrum.

Fig. 12. ¹H spectrum of 2-fluoro-2-deoxyglucose showing ¹⁹F coupling

The coupling patterns are clear in the ¹⁹F spectrum (fig. 13).

Fig. 13. ¹⁹F spectrum of 2-fluoro-2-deoxyglucose showing ¹H coupling

Fluorine couples strongly to ¹³C up to three bonds away (fig. 14). This can bee seen as extra splittings in the ¹³C spectrum

Fig. 14. ¹³C spectrum of 2-fluoro-2-deoxyglucose showing ¹⁹F coupling

Coupling of ¹H to ²⁹Si

Proton silicon coupling is most commonly observed in the TMS signal (fig. 15) but is observed in other silyl compounds. A two bond coupling of 6.6 Hz is typical and the natural abundance of less than 5% for ²⁹Si means that its coupling appears as satellites.

Fig. 15. ¹H signal of TMS showing ¹³C and ²⁹Si couplings as satellite signals