Heat of formation and thermochemical parameters of silole

Total atomization energies and heats of formation of silole, its radicals, cation and protonated forms were calculated using G4 and CCSD(T)/CBS (cc-pV(n+d)Z, n = 2–6) methods. Experimental data for silole are not available. Using ΔHof(Si,298 K) = 107.9 kcal/mol, ΔHfo(298 K) are predicted (±2 kcal/mol): silole: 44, radical cation: 249, Si-radical: 79, C-protonated: 218 and Cα–H radical: 47. Both homolytic and heterolytic dissociations of silole take place at Si. Both C-protonation and hydrogen atom addition preferentially occur at the Cα-site. Thermochemical parameters of silole are: PA = 190 kcal/mol, IE = 8.9 eV, BDE(Si–H) = 86 kcal/mol and deprotonation energy DPE = 362 kcal/mol.