RESUMEN
In the title compound, C8H20N(+)·C3H10B11N2 (-), the carborane anion cage displays nearly-perfect Cs symmetry, with the two CN groups lying on a noncrystallographic mirror plane that bis-ects the cage. In the crystal, the anions form extended chains along the a-axis direction, with C-Hâ¯N hydrogen bonds linking consecutive anions. The C N bond lengths (and B-C N angles) in the nitrile moities are 1.1201â (19)â Å, 178.60â (15)° and 1.1433â (17)â Å, 179.45â (15)°, similar to those observed in organic nitriles. A hydrogen bond between a methylene H atom of the cation and the N atom in one of the nitrile groups of the anion is the closest contact between the anion and cation, at 2.52â Å.
RESUMEN
Microwave-assisted cross-coupling reactions of boron-iodinated derivatives of 1-carba-closo-dodecaborate(1-) (1) with CuCN is shown to cyanate boron vertices of this anion. Clusters with one or two CN groups can be prepared: syntheses of 12-CN-CHB11H10(-) (3) and 7,12-(CN)2-CHB11H9(-) (6) gave yields of 80% and 81%, respectively. The [Et4N](+) salts of 3 and 6 were characterized by NMR, IR, and mass spectroscopies, and the crystal structure of [Et4N]3 was determined by single-crystal X-ray diffraction. Hydrolysis of 3 gave the carboxylic acid 12-COOH-CHB11H10(-) (7).