Synthesis, structural features and molecular docking studies of Cu (II) coordination compounds with 3-arylidene-1-pyrrolines

Journal of Molecular Structure. 2026. Vol. 1349. Article 143748.

Voronina J., Zvereva O., Shmelev M., Chistyakov A., Ekaterina N. Zorina-Tikhonova, Bazhina E., Alexey A. Anisimov, Garifullin B., Rizbayeva T., Gazizov A., Eremenko I.

New copper trifluoroacetate complexes with 3-arylidene-1-pyrrolines as N-donor ligands were synthesized through the interaction of trifluoroacetic acid salts of 3-arylidene-1-pyrrolinium derivatives (L-X, where X = Cl, Br, F, Et, OMe, OEt, Me, OH) with copper acetate. These complexes exhibit diverse structural motifs: Cl- and Br-substituted ligands form coordination polymers featuring octahedrally coordinated copper ions. Ligands bearing -F, -Et, -OMe, and -OEt substituents yield molecular complexes with square-planar copper environments. In the case of L-Me and L-Et derivatives the complexes of five-coordinated copper were obtained due to additional coordination of the water molecule. It is obvious that complexes with water molecules are formed due to their presence in the initial salts or solvent. Periodic quantum-chemical calculations of real and simulated polymeric and molecular complexes of Cu(L)2(CF3COO)2 composition showed that specific type of crystallization for each type of complexes is determined by thermodynamic reasons.

The molecular docking method confirmed that 3-arylidene-1-pyrrolidonium derivatives (both in free and protonated forms) effectively interact with the HER2 receptor, demonstrating significant binding energies. Copper-based coordination compounds exhibit higher binding energies to HER2, indicating their increased potency compared to the parent ligands.

Keywords: crystal structure, topological analysis, 3-arylidene-1-pyrrolines, Complexes, Cu(II), Quantum calculations