The thermal stability of linear oligomers constructed from cubylene units

摘要

The work presents the results of quantum-chemical calculations of linear C8H7-(C8H6) (N) -C8H7 oligomers constructed from cubylene fragments. The stability of these metastable compounds was studied by the molecular dynamics method using the tight binding potential. For oligomers with N = 0, 1, 2, the temperature dependences of lifetimes over the temperature range T = 800-1750 K were determined directly and the activation energies and frequency factors in the Arrhenius equation were calculated. Their stability was found to decrease as N increased. The calculated activation energy for the smallest oligomer possible (N = 0), cubylcubane, was E (a) = 1.6 +/- 0.1 eV. For the linear oligomer comprising four cubylene fragments (N = 2), tetracubyl, it was E (a) = 1.1 +/- 0.1 eV.