| Coupling
Constants |
| Energy level of a
nuclei are affected by covalently-bonded neighbors spin-states |
| three-bond |
| one-bond |
| Spin-States of
covalently-bonded nuclei want to be aligned. |
| +J/4 |
| J (Hz) |
| bb |
| I |
| S |
| ab |
| ba |
| -J/4 |
| S |
| I |
| I S |
| aa |
| +J/4 |
|
|
| The
magnitude of the separation is called coupling constant (J) and has units |
|
| of Hz. |
|