Complexes of the general formula [{4,4'-R2C10H6N2}MS2C6 H3R'], where M = Ni or Pt, R is an alkyl chain, and R' is either a H atom (bdt) or a CH3 group (tdt), were prepared and shown to exhibit thermotropic poly- and mesomorphism. Complexes with short alkyl chains exhibit one or more crystal-to-crystal transitions. Complexes with R =C17H35 and R = H, CH3 (i.e., C-17 Mbdt and C-17 Mtdt) possess soft crystalline phases, which were characterized by optical microscopy, differential scanning calorimetry, and variable temperature X-ray diffraction. The solid-state structures of several members of this series (C(4)Nibdt, C-6 Nibdt, C(4)Ptbdt, C(5)Ptbdt, C(8)Ptbdt, C(13)Ptbdt, and C(17)Pttdt) were also characterized crystallographically. Irrespective of alkyl chain length, these complexes show essentially identical structures at both the molecular and supramolecular level. The inorganic cores form columnar stacks via pi-pi stacking, while the alkyl chains on the periphery of the columns adopt conformations that allow for efficient packing via interdigitation of chains from adjacent columns. Correlation of the phase behavior of these complexes with the solid-state structural information has led to the development of structure-property relationships linking specific structural features to the observed poly- and mesomorphism.