Synthesis and characterization of three novel discotic liquid crystalline derivatives of dibenzo[a,c]phenazine (DBP), substituted at the periphery by four n-hexyloxy chains and a chain of N-alkylene carbazol carboxy group (nC-CAB) containing 3, 6, 11 different carbon chain length are described in this study. All new compounds were characterized by 1H, 13C-NMR, MASS, UV-Vis and PL spectroscopy. Preliminary mesophase characterization is carried out by differential scanning calorimeter (DSC) and polarized optical microscopy (POM). The concentration study of the discotic liquid crystals in dilute solutions shows that all three compounds possess two absorption bands at 335 and 420 nm, which are almost independent of concentration. However, PL spectra operate in different ways. At lower concentrations (less than 1.25 ppm), time resulted PL spectra show that there are three main bands at 375, 480 and 520 nm, which could be ascribed to emissions from carbazole, dibenzo[a,c]phenazine and their complex, respectively. In addition, each band in every compound presents a different decay mode, i.e. emissions from various excitons. In contrast, at higher concentrations (higher than 5 ppm), only a red-shifted broad band at 575 nm is observed, and lifetime study shows it is a single exponential decay. The result of concentration study indicates that the influence of molecular association was shifted from intra-molecular interaction to inter-molecular interaction when concentration was increased from 1.25 ppm to 5 ppm.