Structure and Reactivity of Pure and Hydrogenated C₃₆ by the First-Principles Density Functional Calculation

Abstract

We examined the structures and energies of 15 isomers of C₃₆ using the newly developed first-principles calculation based on the finite-element method (FEM). The Jahn-Teller distortion (D_6h→C_6v) for the isomer with D_6h symmetry is not confirmed in the present calculation, and the isomer with the lowest energy is found to be the one with D_2d symmetry. In experiments, C₃₆ is synthesized as C₃₆H₄ or C₃₆H₆. We calculated the stable structure of C₃₆H_x (x=2, 4, 6, 8) and searched a clue to the question why the hydrogenation process stops at the C₃₆H₆ stage. Consequently, we propose two hydrogenation way up to octahydrogenation. In examing the hydrogenation processes, we conclude C₃₆H₆ is still energetically reactive to hydrogenation.