Structures of N,N′-bis(1,2-dicarba-closo-dodecaboran-1-yl)phenylureas: building blocks for carborane-containing macromolecules

Abstract We report the preparation and structural analysis of carborane-containing diphenylureas ( 1a – c and 2a – c ). The secondary ureas ( 1 ) exist in trans -conformation. In spite of the bulkiness of the carborane cage, the N -methylated ureas ( 2 ) exist in cis -conformation, both in solution and in the solid-state. The results should make it possible to utilize the construction of more complex molecules.