This invention relates generally to organized assemblies of carbon and non-carbon compounds and methods of making such organized structures. In preferred embodiments, the organized structures of the instant invention take the form of nanorods or their aggregate forms. More preferably, a nanorod is made up of a carbon nanotube filled, coated, or both filled and coated by a non-carbon material. This invention is further drawn to the separation of single-wall carbon nanotubes. In particular, it relates to the separation of semiconducting single-wall carbon nanotubes from conducting (or metallic) single-wall carbon nanotubes. It also relates to the separation of single-wall carbon nanotubes according to their chirality and/or diameter.