J Coupling to Other NMR-Active Nuclei

Proton signals will also be split by (J coupled to) other NMR-active nuclei that are nearby in the bonding network. Two commonly encountered spin- /2 nuclei are 19F and 31P (both 100% abundance). Common NMR-active nuclei that must be introduced by isotopic labeling include deuterium (2H, spin 1), and 13C and 15N (both spin Vi). 

Coupling to deuterium, 2H, is observed for deuterated solvents and their residual peaks (from solvent molecules with one 2H replaced by1H).1H-2H coupling constants are proportional to the corresponding H / value, reduced by a factor of about 7 (kh/Kd = 6.51) due to the weaker nuclear magnet of deuterium. Because deuterium has a spin of 1, it has three spins states almost equally populated, and so it splits the H signal into three equal peaks centered on the H chemical shift position. Multiple 2H splittings can be 

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