Unexpected selectivity: [60]Fullerene and CF3I react selectively at 440 °C to synthesize C60(CF3)12. In the product with S6 symmetry, 12 CF3 groups form a continuous loop of alternating para‐ and meta‐C6(CF3)2 hexagons. In the crystal, the chains of molecules are strengthened owing to stacking interactions and shielding effects from the CF3 groups, thus accounting for the low volatility and solubility of the compound.
Unerwartete Selektivität: [60]Fulleren reagiert mit CF3I bei 440 °C selektiv zu C60(CF3)12. In dessen S6‐Isomer bilden die zwölf CF3‐Gruppen eine kontinuierliche Schleife alternierender para‐ und meta‐C6(CF3)2‐Sechsecke. Stapelwechselwirkungen und Abschirmeffekte der CF3‐Gruppen in der Kristallpackung bewirken eine Stärkung der Molekülketten, was die geringe Flüchtigkeit und Löslichkeit der Verbindung erklärt.
Whereas liquid CCl3F reacts with solid AlCl3 exothermically under chlorine-fluorine-exchange already above -20 degrees C, no reaction takes place between CCl3F and the pyridine complexes of AlCl3 (AlCl3.Py, AlCl3.2Py, or AlCl3.3Py) up to 100 degrees C. The desired chlorine by fluorine substitution on the monomer AlCl3-pyridine adducts occurs, however, easily using Me3SiF as fluorinating agent. By reacting AlCl3.3Py with Me3SiF (even up to 10-fold stoichiometric excess) in pyridine as a solvent, only two of the three Cl atoms can be substituted by fluorine, leading in good yield to the new "mixed aluminum halide", AlF2Cl.4Py. Actually, it represents the first example of a stable solid donor-acceptor adduct of an aluminum-III halide with two different halogens of defined stoichiometry. It was characterized by multinuclear solid-state NMR (27Al and 19F), IR spectroscopy, as well as single-crystal structure analysis. The new compound has an ionic solid-state structure with helical trans-octahedral [(Py)4AlF2]+ cations and isolated Cl- anions. The comparison of its 27Al MAS solid-state NMR spectra with those of a compound bearing the analogous [(Py)4AlCl2]+ cation reveals an extreme increase in the quadrupolar coupling constants, from 0.24 MHz in case of the chlorine cation to about 16 MHz in case of the new [(Py)4AlF2]+ cation.
Nanoscopic amorphous Lewis acidic aluminium fluorides, such as aluminium chlorofluoride (ACF) and high‐surface aluminium fluoride (HS‐AlF3), are capable of activating CH bonds of aliphatic hydrocarbons. H/D exchange reactions are catalysed under mild conditions (40 °C).
Two isomers of C70(CF3)12 have been isolated from a mixture obtained by trifluoromethylation of C70 with CF3I; their molecular structures determined by X-ray crystallography are in good agreement with the results of theoretical DFT calculations for the most stable C70(CF3)12 isomers.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.