TOWARD A HEXAGONAL GRID POLYMER - SYNTHESIS, COUPLING, AND CHEMICALLYREVERSIBLE SURFACE-PINNING OF THE STAR CONNECTORS, 1,3,5-C6H3(CB10H10CX)(3)

A synthetic approach to a two-dimensional grid polymer is proposed and the execution of initial steps is described. Pd-catalyzed coupling of (1,12-dicarba-closo-dodecaboran-1-yl)copper (10) with iodobenzene, m- diiodobenzene, and 1,3,5-triiodobenzene yielded the known 1,12-dicarba -closo-dodecaboran-1-ylbenzene (3) and the new m-bis(1,12-dicarba-clos o-dodecaboran-1-y (4) and 5-tris(1,12-dicarba-closo-dodecaboran-1-yl)b enzene (1), yl)benzene (1), respectively. Each arm of the trigonal con nector 1 was provided with one or two sticky tentacles by conversion t o ilyl)-1,12-dicarba-closo-dodecarboran-1-yl]benzene (7) and ilyl)-1,1 2-dicarba-closo-dodecarboran-1-yl]benzene (8). Linear coupling of carb oranyl CH terminals through a mercury atom produced very stable dimeri c structures from 3 and 4. The carborane 3, its mercury-linked dimer 1 3, the 1:1 complex of 13 with 2,2'-bipyridyl, and the 2:1 complex of 1 3 with 2,2'-bipyrimidyl have been structurally characterized by single -crystal X-ray crystallography, but crystals of 1 showed an intriguing disorder and could not be used for molecular structure determination. Grazing incidence IR spectra show that the tentacled species 7 and 8 adsorb firmly on the surface of gold, apparently without a strong pref erence for a particular orientation. At room temperature, the tritenta cled species 7 can be removed readily and the hexatentacled species 8 more slowly by treatment with a THF solution containing fluoride, whic h severs the tentacles.