Theoretical study of two C₃₀H₂₀ isomers with a dodecahedrane cage and two pentaprismane cages sharing two pentagons

Abstract

Structures, energies, and vibrational frequencies have been calculated for two C 30 H 20 isomers with a dodecahedrane cage and two pentaprismane cages at the B3LYP/6-31G* level of theory. Thus, two C 30 H 20 isomers have the form of coplanar tricage molecules. The symmetry of one C 30 H 20 isomer is of D 5d and that of another is of C 2V . The heat of formation for two C 30 H 20 isomers have been estimated. Heats of formation of two C 30 H 20 isomers as well as the vibrational analysis indicate that two C 30 H 20 isomers enjoy sufficient stability to allow for its experimental preparation.

Dodecahedrane minibead polymers

“…37 The fusion of dodecahedrane rings has been predicted to be possible by theoretical studies on the C 25 H 20 molecule with a dodecahedrane and pentaprismane cage sharing the same pentagon 38 and with C 30 H 20 and C 35 H 30 isomers of coplanar tricage molecules sharing two pentagons. 39,40 The heat of formation of tri-cage molecules provides sufficient stability for such experimental preparations. 39,40 The fusion of dodecahedrane rings could be solved by replacing the hydrogen atoms of dodecahedrane (C 20 H 20 ) with relatively weakly bound bromine atoms, followed by gas phase debromination similar to that applied for the production of the smallest fullerene, C20.…”

“…39,40 The heat of formation of tri-cage molecules provides sufficient stability for such experimental preparations. 39,40 The fusion of dodecahedrane rings could be solved by replacing the hydrogen atoms of dodecahedrane (C 20 H 20 ) with relatively weakly bound bromine atoms, followed by gas phase debromination similar to that applied for the production of the smallest fullerene, C20. As a possible solution for the annealing of two dodecahedrane beads, the bromination of dodecahedrane generating a series of C 20 Br n À clusters with n ranging from 13 to 0 (ref.…”