Rong-Bin Huang

Carboncones, a special family of all-carbon allotropes, are predicted to have unique properties that distinguish them from fullerenes, carbon nanotubes, and graphenes. Owing to the absence of methods to synthesize atomically well-defined carboncones, however, experimental insight into the nature of pure carboncones has been inaccessible. Herein, we describe a facile synthesis of an atomically well-defined carboncone[1,2] (C₇₀H₂₀) and its soluble penta-mesityl derivative. Identified by x-ray crystallography, the carbon skeleton is a carboncone with the largest possible apex angle. Much of the structural strain is overcome in the final step of converting the bowl-shaped precursor into the rigid carboncone under mild reaction conditions. This work provides a research opportunity for investigations of atomically precise single-layered carboncones having even higher cone walls and/or smaller apex angles.

Achiral ligand- and Ag(I)-driven spontaneous resolution occurred simultaneously in the formation of two enantiomers 1P and 1M of [Ag₂(5-nip)(mpyz)] (5-nip = 5-nitroisophthalic, mpyz = 2,3,5,6-tetramethylpyrazine), whose absolute sense of a helix made of achiral components is induced by the metal Ag(I) through argentophilic interactions.

The title compound, C₂₂H₂₉F₃O₅S [systematic name: (3S,8R,9S,10R,13S,14S)-10,13-dimethyl-17-(trifluoromethylsulfonyloxy)-2,3,4,7,8,9,10,11,12,13,14,15-dodecahydro-1H-cyclopenta[a]phenanthren-3-yl acetate], contains a fused four-ring steroidal system. RingsAandCadopt a chair conformation, while ringsBandDadopt half-chair and envelope (with the fused CH atom as the flap) conformations, respectively. In the crystal, weak intermolecular C—H...O interactions link the molecules into layers parallel to theabplane.