Negative Volume Compressibility in ScN@C-Cubane Cocrystal with Charge Transfer.

According to the laws of thermodynamics, materials normally exhibit contraction or expansion along the directions of the applied pressure or tension. Here, we show that a man-made cocrystal of a metallofullerene and highly energetic cubane, with strained sp bonding, may exhibit an anomalous negative compressibility. In this cocrystal, the freely rotating fullerene ScN@C acts as a structural building block while static cubane molecules fill the lattice interstitial sites.

From Methyl Radical to Polyacetylene: Size-Dependent Structural Properties of Linear Polyenes.

Hydrocarbons and nanostructures, consisting of trigonally coordinated C-atoms, represent a huge family of functional materials. Depending on the configuration and the size, they may be highreactivity intermediates, raw materials or catalyzers of organic reactions, or semiconducting polymers with variable bandgap. Small molecules have been intensively studied by chemists, and crystalline polymers by physicist, but the knowledge on the medium-size oligomers is rather incomplete.

New Ordered Structure of Amorphous Carbon Clusters Induced by Fullerene-Cubane Reactions.

As a new category of solids, crystalline materials constructed with amorphous building blocks expand the structure categorization of solids, for which designing such new structures and understanding the corresponding formation mechanisms are fundamentally important. Unlike previous reports, new amorphous carbon clusters constructed ordered carbon phases are found here by compressing C H /C cocrystals, in which the highly energetic cubane (C H ) exhibits unusual roles as to the structure formation and transformations under pressure. The significant role of C H is to stabilize the boundary interactions of the highly compressed or collapsed C clusters which preserves their long-range ordered arrangement up to 45 GPa.

Crystal structure of the 4 + 2 cyclo-adduct of photooxidized anthracene and C60 fullerene.

The structure of the title compound, 5,6-[(1R,10S)-2,9-dioxatri-cyclo-[8.6.0(3,8).

Orientational ordering and low-temperature libration in the rotor-stator cocrystals of fullerenes and cubane.

Cocrystals of cubane and fullerenes, C60-cubane and C70-cubane, show distinct rotational ordering transitions. We studied the corresponding structural changes with temperature-dependent X-ray diffraction and the thermodynamics of the phase transitions with adiabatic microcalorimetry and differential scanning calorimetry. C60-cubane has one phase transition around 130 K from a high-temperature fcc phase with freely rotating C60 to a low-temperature orthorombic phase in which the fullerene rotation is frozen.