Quantum-chemical calculations of primary reactions of cyclopentadienone thermolysis

Quantum-chemical calculations by the CCSD(T)-F12/vtz-f12В method are used to find the geometric structure and determining the frequency of oscillations and the energy of reactants, products, transitional states, and reactions of decomposition of C$_5$H$_4$O. The calculated energy barriers for two most probable paths of the C$_5$H$_4$O pyrolysis reaction, which are equal to 96.3 and 96.5 kcal/mole, confirm that pyrolysis proceeds at a high temperature, and the most probable decomposition products are vinylacetylene and carbon monoxide. The formation of such products as cyclobutadiene, acetylene, and propadienal can be explained by realization of the energetically beneficial path.