ქიმიის ტერმინთა განმარტებითი ლექსიკონი

Effect of the relative orientation of the magnetic fields of adjacent nuclei on each other and the resultant splitting of their signals in nuclear magnetic resonance spectroscopy (multiplicity).

Note 1:   For 2 proximal nuclei A and B, magnetic field at nucleus A is the sum of the nuclear  shielding and the  magnetic field at nucleus  B.  If nucleus B has two possible orientations in field due to spin 1/2 then nucleus A will experience 2 possible magnetic fields and therefore give 2 distinct frequencies. The frequency difference between these two lines is called the spin–spin coupling constant JAB.

Note 2: Spin–spin coupling is transmitted through intervening bonding electrons, in contrast to the through space dipolar mechanism.

Note 3: SI unit: Hz.