Topochemical polymerization of C-70 controlled by monomer crystal packing

Polymeric forms of C-60 are now welt known, but numerous attempts to obtain C-70 in a polymeric state have yielded only dimers. Polymeric C-70 has now been synthesized by treatment of hexagonally packed C-70 single crystals u nder moderate hydrostatic pressure (2 gigapascals) at elevated temperature (300 degreesC), which confirms predictions from our modeling of polymeric s tructures of C-70 Single-crystal x-ray diffraction shows that the molecules are bridged into polymeric zigzag chains that extend along the c axis of t he parent structure. Solid-state nuclear magnetic resonance and Raman data provide evidence for covalent chemical bonding between the C-70 cages.