Synthesis, structure, and properties of a polymeric copper(II) complex with anion of maleic acid

A new polymeric copper(II)-maleato complex, used as a dicarboxylate ligand, was synthesized {Na2[Cu(C4H2O4)2]2H2O}n (1). The resulting complex was characterized by elemental analysis, infrared and UV-visible spectroscopy, and X-ray crystallography. Spectroscopic data indicate that the maleato ion coordinates in a chelating bidentate mode, creating a distorted square planar coordination environment around Cu(II). X-ray crystallography confirmed the formulation (1) and revealed that the central Cu(II) ion is in a distorted square planar. The maleato ion acts as a bidentate chelator, coordinating through two carboxylate oxygens to form a stable four-membered ring. This study extends our understanding of the coordination behavior of pi-conjugated dicarboxylic acids with transition-metal ions. Molecular docking studies demonstrated that the polymeric copper(II)-maleic acid complex exhibited strong binding affinity toward B-DNA (1BNA), with a binding energy of - 10.2 kcal/mol and multiple stable hydrogen bond interactions. The molecular docking results demonstrated that the polymeric copper(II) complex with maleic acid forms conventional hydrogen bonds with B-DNA. Specifically, interactions were observed with guanine and cytosine bases: the O2 atom of cytosine (DC21), the O4 ' atom of guanine (DG24), and the hydrogen atoms of guanine residues DG2, DG4, and DG22. The hydrogen bond distances (2.10-2.89 & Aring;) confirm the stability of these interactions. Moreover, several of these interactions are located within or near the minor groove of DNA, indicating a groove-binding mode. In addition, the complex exhibits an intramolecular hydrogen bond that stabilizes its conformation during binding.