Structures of bis- and tris(2-phenyl-o-carboran-1-yl)benzenes. Construction of three-dimensional structures converted from planar arylacetylenic arrays

Compounds (1–3), which are composed of benzene nuclei linked through 1,2-dicarba-closo-dodecaborane (o-carborane), were synthesized and their structures were determined by X-ray crystallography. 1,3-Bis(2-phenyl-o-carboran-1-yl)benzene and 1,3,5-tris(2-phenyl-o-carboran-1-yl)benzene (3) have syn stereochemistry of all the terminal benzene rings, despite their steric overcrowding.