Dinuclear Copper(II) and Molybdenum(VI) Complexes of Bis‐Tridentate Hydrazonylthiophene: Synthesis and Biochemical Evaluation

ABSTRACT An economical multidentate 2,5‐dicarbohydrazide‐(2‐hydroxybenzylidene)thiophene ligand (HL) was synthesized in a facile way. For the coordination capability, HL bonded to Cu 2+ and cis ‐MoO 2 2+ cations for the design of two new complexes of CuL and cis ‐MoO 2 L, respectively. The inhibitive action of HL (as a free organic reagent) impacted by its complexing forms in CuL and cis ‐MoO 2 L on the proliferating capacity of various microorganism series and normal/tumor cell lines of humankind was examined, and their antioxidant capacity was evaluated. Consequently, Cu 2+ and cis ‐MoO 2 2+ cations exhibited modified biochemical actions against the developed proliferation of the bacterial‐fungal and tumor cells over the uncoordinated HL ligand through the measured areas of microorganisms’ dead zones (mm) and the half‐maximal inhibitory concentrations ( IC 50 , µM) of the proliferated tumor cell lines in vitro, spectroscopically. The affinity of binding strength and modes of HL, CuL, and cis ‐MoO 2 L with calf thymus DNA (ctDNA) were estimated by the variations in the viscometric and colorimetric characteristics of the current compounds, referring to the obvious effect of Cu 2+ and cis ‐MoO 2 2+ cations with their high electronegativity and redox potential. Spectroscopic analyses were employed to examine the interaction of HL, CuL, and cis ‐MoO 2 L with ctDNA through the derived data of K b and , as 1.31, 1.55, and 1.61 × 10 6 mol − 1 dm 3 , and as −40.14, −44.38, and −45.43 kJ mol − 1 , respectively. Hence, Cu 2+ and cis ‐MoO 2 2+ cations demonstrated a significant influence on the biological action of their complexes based on their different charges, oxidation states, and coordination geometries relative to the uncoordinated organic HL ligand.