A Simple Theory of 13C Nuclear Spin Diffusion in Organic Solids

We derive an expression for the rate of spin diffusion between ¹³C nuclei based on a simple model appropriate for organic solids. In this model, couplings between carbons and protons and among protons are included only as a source of fluctuating local magnetic fields at the carbon nuclei. Our results are essentially equivalent to the results of previous calculations in which the surrounding protons are treated quantum mechanically using memory function formalisms.