AN M-CARBORANEDICARBOXYLIC ACID DIANILIDE

The crystal structure of the 'non hydrogen-bonded' (according to IR da ta) polymorph of enylcarbamoyl)-1,7-dicarba-closo-dodecaborane(12), C1 6H22B10N2O2, has been determined. The two phenylamide groups have a Z configuration [the torsion angles O-C-N-C are -2.3 (5) and -3.0(5)degr ees]. As a result both 'active' protons of these groups are almost com pletely shielded by other H atoms of the neighbouring carborane nucleu s and phenyl substituents, and, therefore, no hydrogen-bonding contact s are found.