2-(2-amino-4,10-dihydrobenzo[4,5]imidazo[1,2-a][1,3,5]triazin-4-yl)phenol (ligand) and its related metal complexes of Mn (II), Co (II), Ni (II), Cu (II) and Zn (II) were prepared under microwave irradiation. The structures of prepared compounds were elucidated in terms of elemental analysis, FT-IR, UV-Vis, 1HNMR, 13CNMR, EPR spectra and mass spectra in addition to magnetic studies at room temperature and thermal properties. Elemental analysis results determined mole ratios between the ligand and metal 1:1 or 1:2. The microwave approach provides clean, shorter reaction times and enhancements in yields. Coats Redfern and Horowitz Metzger equation were used to study Thermal kinetic parameters of dehydration and decomposition of the complexes. The geometries of the ligand and its Mn (II), Co (II), Cu (II) and Zn (II) complexes were optimized using Gaussian 09 W; density functional theory (DFT) B3LYP method. Also, the cytotoxic activity of the ligand and its metal complexes were evaluated against liver cancer cells (HepG-2) and the Cu (II) complex exhibited the highest cytotoxic activity with promising IC50 value = 3.5 µg/ml compared to standard reference cisplatin.