| Popis: |
Structural data about linear carbon modifications within the span of more than 30 years of rather ‘mysterious’ carbyne history were analyzed. A two-dimensional structure with a hexagonal parameter a = 505–525 pm is considered the basis for all carbyne modifications. The large value of this parameter, larger than a 300 pm-van der Waals diameter of sp-carbon atoms, is accounted for by the existence of regular vacancies. The three-dimensional packing of zigzag-like carbon chains with a 31/2×31/2 vacancy superlattice is an ideal matrix for doping with metals. The capture of metal atoms during crystallization stabilizes additionally linear carbon chains in the solid state. Finally, a polycrystalline mosaic structure of carbyne macrocrystals is proposed that can explain the textured (spotted) diffraction pattern of hexagonal type observed experimentally. |
