The treatment of N-Phenylmorpholine-4-carbothioamide (HPMCT) with bivalent metal ions in a 2:1 mol ratio without a base present affords [MCl2(κ1S-HPMCT)2] {M = Cu(1), Pd(2), Pt(3), and Hg(4)} in a good yield. Furthermore, the reaction of two equivalents of HPMCT and one equivalent of bivalent metal ions in the presence of Et3N has afforded [M(κ2S,N-PMCT)2] {M = Ni(5), Cu(6), Pd(7), Pt(8), Zn(9), Cd(10), and Hg(11)}. Infrared, 1H, 13C Nuclear Magnetic Resonance molar conductivity, and elemental analysis were used to characterize the synthesized complexes. The results suggest that HPMCT is bonded as monodentate via an S atom in Complexes (1–4), whereas linkage as a bidentate chelating ligand via S and N atoms gives two chelate rings. Moreover, the synthesized ligand and the complexes were screened for antibacterial activity, which displayed that the very best antibacterial activities for Complexes (1), (6), and (3). In addition, the cytotoxic activity of the HPMCT ligand, [PdCl2(HPMCT)2] (2), and [PtCl2(HPMCT)2] (3) were screened on breast cancer cell lines (MCF-7), and Complex (3) reveals the most promising activity with an IC50 value 12.72 ± 0.4 μM. Using the B3LYP method and 6-311++G(d,p) basis sets for the ligand and the SDD basis set for the central metal, the synthesized complexes utilizing the prepared ligand were optimized. Various quantum parameters such as hardness, electron affinity, dipole moment, vibrational frequencies, and ionization energy for the ligand and its complexes have been calculated. In general, a favorable agreement was found between the experimental results and the obtained theoretical results.