The crystal structures of E, E-1,4-bis[2-(2,4,6-trimethoxyphenyl)ethenyl]-2,5-dimethoxybenzene (1), E, E-1,4-bis[2-(2,4,6-trimethoxyphenyl)ethenyl]-2,5-diisopropoxybenzene (2), E, E-1,4-bis[2-(2,4,6-trimethoxyphenyl)ethenyl]-2,5-dihexoxybenzene (3), and E, E-1,4-bis[2-(2,4,6-trimethoxyphenyl)ethenyl]-2,5-bis(2-phenylethoxy)benzene (4) are reported. A weak intramolecular hydrogen bond between protons on the olefinic link and the ortho-methoxy groups on the adjacent benzene rings is commented on. In general, however, the crystal packing for these structures is primarily determined by weak -OCH 3 -π interactions. Their numbers change with the structure and length of the side chains and with the accommodation of the extended chains in the lattice. A discussion on the effects of these interactions on the possibility of lattice formation explains why these four compounds crystallize and several similar ones with different alkoxy side chains do not.

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The title compound, C30H34O8, crystallizes in the space group P-1 with one-half of a molecule in the asymmetric unit. A three-dimensional network is generated by OCH3...pi and CH...pi interactions. The conformation of the C-C bond exocyclic to the central benzene ring is different from that of every other known derivative. A comparison of the geometry of the title molecule and of its solid-state structure with other 2,4,6-trimethoxy-substituted PPV [i.e. poly(p-phenylenevinylene)] oligomers, in particular the isopropoxy-substituted compound, is provided.

A novel class of self-doping conjugated oligomers, E,E-2-(sulfoalkoxy)-5-alkoxy-1,4-bis [2-(2,4,6-trimethoxyphenyl) ethenyl]benzenes, is presented. The synthesis and spectroscopic characterisation of five such oligomers are described, and an electrochemical analysis using cyclic voltammetry is performed to determine the anodic peak potentials. A structural study is performed on six self-doping oligomers in which the structures and energies of the possible mono-molecular forms of the electrically conducting doped material are described and evaluated using Hirshfeld charges and the Quantum Theory of Atoms In Molecules.