Chemical and structural analogs of sp2 nanocarbons The sp2 carbon masterpiece presented in this book will not be complete if we do not touch on the question regarding chemical and structural analogs of the carbons. First, it concerns siliceous counterparts, the discussion of which was a topic of large interest, since numerous attempts to get siliceous fullerene, nanotubes, and graphene were unsuccessful. Otherwise, there are fullerene-like, tube-like, and graphene-like structures of differ ent halcogenides and boron nitride, while the atoms that form these structures are not analogous to carbon. We will briešy consider the basic grounds that lay the foundation of the species behavior and will try to explain their drastic difference from carboneous species.