Synthesis, Morphology, and Optical Properties of Tetrahedral Oligo(phenylenevinylene) Materials

A novel topological strategy is described for designing amorphous molecular solids suitable for optoelectronic applications. In this approach, chromophores are attached to a tetrahdral point of convergence. Stilbenoid units were covalently linked to tetraphenylmethane, tetraphenyladamantane, or tetraphenylsilane cores using palladium catalyzed coupling methodology. Thus, reaction of E(C6H5X)4 (E = C and adamantane, X = I; E = Si, X = Br) with styrene or 4,4‘-tert-butylvinylstilbene under Heck coupling conditions yields the corresponding tetrakis(stilbenyl) (E(STB)4) and tetrakis(4-tert-butylstyrylstilbenyl) (E(tBuSSB)4) compounds. Similarly, reaction of 1,1-diphenyl-2-(4-dihydroxyboronphenyl)ethene or 2-(4-pinacolatoboronphenyl)-3,3-diphenylacrylonitrile with tetrakis(4-bromophenyl)methane using Suzuki coupling methodology gives tetrakis(4,4‘-(2,2-diphenyl-vinyl)-1,1‘-biphenyl)methane (C(DPVBi)4) or tetrakis(4,4‘-(3,3-diphenylacrylonitrile)-1,1‘-biphenyl)methane (C(DPAB)4), respectively, in good yields. C...