Theoretical study of tricyclo[3,3,1,1]decane, tricyclo[3,3,1,1]decsilane molecules and their halogen derivatives, C10H12X4 and Si10H12X4 (X=F, Cl, Br, I)

The B3LYP/3-21G* ab initio molecular orbital method from the program package was applied to study tricyclo3,3,1,1^3,7]decane and tricyclo3,3,1,1^3,7]decsilane molecules and their halogen derivatives (1,3,5,7-tetrahalotricyclo3,3,1,1^3,7]decane and 1,3,5,7-tetrahalotricyclo3,3,1,1^3,7]decsilane, C₁₀H₁₂X₄ and Si₁₀H₁₂X₄ respectively). The optimized structures of these compounds were obtained. Ionization potentials, HOMO and LUMO energies, energy gaps, heats of formation, atomization energies and vibration frequencies were calculated. The calculations indicate that these molecules are stable and have T_d symmetry. Tricyclo3,3,1,1^3,7]decsilane and its halogen derivatives (Si₁₀H₁₂X₄) are found to have higher conductivity than tricyclo3,3,1,1^3,7]decane and its halogen derivatives (C₁₀H₁₂X₄). 1,3,5,7-Tetrafluorotricyclo3,3,1,1^3,7]decane (C₁₀H₁₂F₄) and 1,3,5,7-tetrafluorotricyclo3,3,1,1^3,7]decsilane (Si₁₀H₁₂F₄) were found to be the easiest compounds to form and the most difficult to dissociate of all 1,3,5,7-tetrahalotricyclo3,3,1,1^3,7]decane and 1,3,5,7-tetrahalotricyclo3,3,1,1^3,7]decsilane compounds, respectively.