In this study, we have compared the well known N3 dye and Ru(II) complex substituted with antenna group, such as two pyrenes of both site to bipyridine. Molecular orbital analysis confirmed that the LUMO and LUMO+1 are essentially delocalized over the dcbpy and the antenna ligand, respectively. The TD-DFT calculations showed that the complex with pyrene antenna had more panchromatic absorption spectra in the region above 400 nm compared to N3 dye. Moreover, the absorption bands around between 400 and 550 nm were red-shifted and increase molar extinction coefficients due to the antenna unit.