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A series of penta(p-phenylene)s modified with short and long alkoxy groups was synthesized via palladium complex-catalysed cross-coupling reactions. Molecules substituted with butoxy groups in the central ring showed a nematic phase characterized by a schlieren optical texture, whereas those molecules lacking lateral groups, or substituted with shorter than butoxy groups, did not exhibit liquid crystallinity. Also, it was determined that both the mesophase stability and the clearing point were strongly dependent on the length of the terminal chains. Finally, optical studies of these compounds indicated that the observed light absorption/ emission characteristics are independent of the chain lengths. [ABSTRACT FROM AUTHOR]