The new polymers can be semiconducting or metallic but no superconductivity has been observed sofar. Polymerization has been reported for C60 but also for C70 cages. Threedimensional polymerization can leed to ultrahard material , material which is harder than diamond. Doping of the polymer can be performed by intercalation of electron donors inbetween the cages but also by substitution of carbon atoms by donors on the cage. For dimers intercalation doped systems and substitution doped systems exhibit very similar electronic properties.
Doped polymers can have very unusual magnetic properties.
Such materials exhibit an other class of new fullerenic materials. The endohedral chemistry of such systems was found to be quite different to the conventional exohedral chemistry. Typical values of the former are 1.4 nm. With respect to the latter semiconducting tubes , narrow gap tubes and metallic tubes are known. The extension of the described systmes is exactly ondimensional with respect to its periodicity in space.