Adamantane template effect on the self-assembly of a molecular tetrahedron: A theoretical analysis

The Structure of Adamantane Clusters: Atomistic vs. Coarse-Grained Predictions From Global Optimization

Candidate structures for the global minima of adamantane clusters, (C₁₀H₁₆)_N, are presented. Based on a rigid model for individual molecules with atom-atom pairwise interactions that include Lennard-Jones and Coulomb contributions, low-energy structures were obtained up to N = 42 using the basin-hopping method. The results indicate that adamantane clusters initially grow accordingly with an icosahedral packing scheme, followed above N = 14 by a structural transition toward face-centered cubic structures. The special stabilities obtained at N = 13, 19, and 38 are consistent with these two structural families, and agree with recent mass spectrometry measurements on cationic adamantane clusters. Coarse-graining the intermolecular potential by averaging over all possible orientations only partially confirm the all-atom results, the magic numbers at 13 and 38 being preserved. However, the details near the structural transition are not captured well, because despite their high symmetry the adamantane molecules are still rather anisotropic.

Molecular Dynamics Study on Dynamical Features of Reorganization Process for Nanocapsule Formed with Gear-Shaped Amphiphile Molecules

We have analyzed the dynamical feature of a hexameric structure of nanocube (1₆) from a gear-shaped amphiphile molecule (1) upon addition of solvophobic spherical adamantane molecule (G), by means of molecular dynamics (MD) simulation, to elucidate the conversion mechanism from the hexameric nanocube G@1₆ to a tetrameric G@1₄ tetrahedron. The adamantane molecule (G) in the nanocube G@1₆ is located around the triple π stacking, although G in the G@1₄ tetrahedron is at the central position of the capsule. Our MD simulation shows that the nanocube G@1₆ is more fluctuated than the G@1₄ tetrahedron. We have also found that a demethylated nanocube G@2₆ is converted to a tetrameric G@2₃ tetrahedron due to the solvophobic effect for the adamantane molecule.