In this study, we carried out theoretical study of electronic properties and geometry of twelve conjugated compounds based on 1,3-diaza-azulene. The effect of the substituted groups (Cl, F, Br, CH3) on the optoelectronic and structural properties, dipole moment, HOMO, LUMO and Egap are discussed. The geometry at the ground state and the electronic structure of studied molecules are obtained by density functional theory (DFT) and density functional theory time-dependent (TD-DFT) with the B3LYP / 6-31G (d, p). The results of this study show that these compounds are good candidates for organic solar cells.