© 2018, Pleiades Publishing, Ltd.In this study, two ligands and their ruthenium complexes are synthesized and their photovoltaic properties for dye-sensitized solar cells (DSSCs) of new substances substituted by 4,5-diazafluorenone-9-hydrazone groups is investigated. The structures of the compounds are determined by FTIR, UV-Vis, HNMR, CNMR, and MS spectroscopic techniques. The photovoltaic and electrochemical properties of these compounds are investigated and the applicability in DSSCs as photo sensitizers is studied. Photovoltaic cell efficiencies (PCEs) of the devices are in the range 0.08-1.54% under simulated AM 1.5 solar irradiation of 100 mW/cm2, and the highest open-circuit voltage (Voc) reaches 0.43 V. When the photovoltaic performance of the DSSC devices is compared, it indicates that PCEs assume the following: P1–Ru > > P2–Ru > P1 > P2. The PCE value of 1.54% is obtained with DSSC based on P1–Ru under AM irradiation (100 mW/cm2). DSSC based on the P1–Ru produced efficiency of 1.54% whereas DSSC-based P1 exhibits the device performance with an efficiency of 0.08% under illumination. These results suggest that a larger π-conjugated bridge and a richer electron donor of P1–Ru are beneficial for the photovoltaic performance of DSSC.