Thermal averaging of the spin-rotation coupling in small molecules leads to an isotropic NMR shielding

► The spin-rotation interaction does not thermally average to zero at high field. ► The super-spin-rotation coupling is linear in the field. ► The super-spin-rotation coupling is usually temperature-independent. ► The super-spin-rotation coupling can be up to 0.3 ppm. ► The super-spin-rotation rapidly goes to zero as molecular size increases.