A series of mono-nuclear ruthenium arene complexes with thiosemicarbazones (TSCs) ligands (A-type, 1–8) and their corresponding di-nuclear analogues (B-type, 9–16) were synthesized and characterized by NMR, elemental analysis and HR-ESI-mass spectrometry. The molecular structures of 1, 2, 6, 9–11 and 13–16 were determined using single-crystal X-ray diffraction analysis. The nature of the two types of complexes was studied using density functional theory (DFT) calculations.