The reaction between [RuHCl(CO)(PPh3)(3)] and 2-methyl-4(5)-nitroimidazole (L) has been performed and the hydride carbonyl ruthenium(II) complex [RuH(CO)(PPh3)(2)(L)] has been obtained by this reaction, running with deprotonation of the ligand. The molecular structure of the complex has been determined by X-ray crystallography and its spectroscopic characterization has been carried out by IR, H-1, P-31 and C-13 NMR, UV-Vis spectroscopy. Supported by the DFT computational method, the electronic structure is described in order to explain the absorption and emission spectra obtained experimentally. The luminescence property of the complex has been examined and the quantum yield of the fluorescence has been obtained by a comparative method. The observable fluorescence is related to MLLCT excited states. The imidazole derivative ligand plays a role in the creation of the excited states.