The interlayer complexes of several methyl methacrylate (MMA)/2-(N-methyl-N,N-diethylammonium iodide) ethyl acrylate (MDEA) copolymers with two smectite clays (bentonite and hectorite), synthesized in two different ways, were studied by means of solid state C-13 n.m.r. techniques. Given the relatively high content of paramagnetic centres in bentonite, which is approximately 50 times more paramagnetic than hectorite, the s.p.e./m.a.s. and c.p./m.a.s. spectra of the different complexes with bentonite show differences according to the proximity of the different copolymer moieties to the clay surface. The dynamics of the organic macromolecules in the inorganic interlayers has been investigated by measuring various relaxation times (C-13 T-1, C-13 T-1 rho and H-1 T-1 rho). The paramagnetism of the clay, where relevant, strongly influences the relaxation times measured, whereas in the other cases the different relaxation times allow one to discern differences in the structural organization and mobility of the organic macromolecules depending on the complex preparation. Useful indications on the structure of the different complexes have been obtained by combining the above results with X-ray measurements of the interlayer distance for all the samples investigated.