New derivatives of the all-aromatic liquid crystal p-quinquephenyl were synthesized via a series of palladium-catalyzed cross-coupling reactions and their thermal and photophysical properties were investigated as a function of their molecular geometries.  Deviations from the parent poly(p-phenylenes) (PPP_nPP, n = 1, 2, and 3) include substituting two heterocyclic rings such as oxadiazole(O), 2,5-thiophene(T), or 2,4-thiophene(t) and lengthening of the core phenylenes as para, meta, and ortho conformers.  In general, introducing nonlinearity depresses the melting transition temperatures.  Increasing the molecular length (from five to six and to seven aromatics) by adding p-phenylenes to the core, stabilizes a broader nematic range.  For the seven ring system p-POPPPOP, the 1,3- and 1,2-bisphenyl analogues, m-POPPPOP and o-POPPPOP, respectively, exhibit dramatic decreases in phase behavior.  In fact, o-POPPPOP forms a glass.  When conjugation is perturbed in the form of a 1,3-phenyl or 2,4-thiophene substitution (m-POPPPOP and PtPPtP, respectively), no mesophase behavior is observed.  There are corresponding changes in the UV absorption and fluorescence spectra of these aromatic mesogens. Our findings enable us to begin to separate electrostatic and shape contributions to phase preferences.