The mesophase properties of bis(5-alkoxytropolonato)copper(II) complexes are reported and interpreted in terms of d-layer spacings, which indicate considerable intertwining of the alkyl chains. The mesogenic properties depend on the nature of the 5-substituent to be mesogenic, it must be alkoxy with n > 8, and may not be 5-alkanoyl or 5-alkylamino. The nature of the metal is also important: to be mesogenic, it may be Cu-II or UO2VI but not Ni-II, Zn-II, Co-II, or VOIV. The crystal structure of bis(5-hexadecyloxytropolonato)copper(II) shows how, even in the crystalline state, molecular packing is dominated by the interactions between alkyl chains, together with copper-oxygen interactions, In the Cu-II complexes, strong interactions occur between Cu atoms and O atoms of neighboring molecules. These are stronger than alkyl-alkyl interactions and therefore dominate alkyl-alkyl interactions between neighbors which otherwise govern the possibility and nature of mesogenic properties. The Cu(...)0 interactions disrupt alkyl-alkyl chain interactions enough to produce a mesophase; such interactions do not obtain in the T-d Zn-II and Co-II complexes, and indeed, these complexes are not mesogenic. Likewise, alkyl chain Interactions by the oxygens of the UO2VI lead to a mesophase, and U constitutes the heaviest metal ever placed into a mesogenic molecule. In the case of VOIV, analogous synthetic steps from VOSO4 led to a new series of binuclear complexes [(VO)(2)(SO4)(5-alkoxytropoloato)(2)].