Self-assembled "supra-molecular" liquid-crystalline phases were investigated in one of aseries of symmetrically tapered bisamides based on an amide core of 1,2-bis[3,4,5-tris(alkan-1-yloxy)benzamido]benzene and three alkyl tails on each side of the core. One of this seriesof bisamides having 14 carbon atoms in each tail (abbreviated as C
14PhBA) served as anexample in this study. Differential scanning calorimetry thermal diagrams showed two mainphase transition processes in C
14PhBA. Wide-angle X-ray diffraction results revealed thatthe high-temperature phase transition is between the isotropic melt (I) and a 2D low-orderedoblique columnar phase (I
OB). The low-temperature phase transition was attributed tothe transition between a highly ordered, oblique columnar (
OK) phase and the
OB phase.Supra-molecular columns were directly visualized using transmission electron microscopyand atomic force microscopy. The formation of these supra-molecular structures is criticallydependent upon the construction of building blocks ("columns") by C
14PhBA molecules. Thesebuilding blocks developed via rigid amide core/alkyl tail micro-phase separation and thehydrogen (H) bond formation between the N-H and carbonyl groups among the cores.Spectroscopic studies showed that the columns were stabilized by intercore H-bonds orientedalong the column long axis, and the alkyl tails in the
OK phase were packed into an orderedmesophase having about 64% of the methylene carbon atoms in long trans segments at roomtemperature. In the
OB phase, the alkyl tails adopt liquidlike disordered conformations.The high- and low-temperature phase transitions were thus mainly attributed to the suddenchanges in H-bonding and alkyl tail conformation, respectively. A detailed packing model ofthe
OK phase was proposed and qualitatively proven using a simulated structural diffraction.