Self‐assembly of unexpected [Mn(2‐(1‐hydrazonoethyl)pyridine)Cl2]n 1D coordination polymer: Synthesis, structural elucidation, and biological studies

Abstract

Self‐assembly of (((1‐(pyridin‐2‐yl)ethylidene)hydrazono)methyl)phenol ligand (L1) and MnCl2 proceeded with the hydrolysis of the ligand affording the new [Mn(L2)Cl2]n 1D coordination polymer where L2 is 2‐(1‐hydrazonoethyl)pyridine. The structure of [Mn(L2)Cl2]n was confirmed using FTIR, CHN, and X‐ray diffraction of single crystal. It crystallized in the triclinic P‐1 crystal system with a = 7.0697(9) Å, b = 8.878(1) Å, c = 9.402(2) Å, α = 113.99(2)°, β = 95.48(1)°, γ = 111.77(1)°, and V = 479.13(15) Å3. The Mn(II) is octahedrally coordinated with two nitrogen atoms from L2 and four chloride ions. The chloride anions act as bridging ligand that connect the Mn(II) centers leading to the formation of the 1D polymer. Based on continuous shape (CShM) measure tool, the coordination configuration is closer to the octahedron rather than a trigonal prism. Using Hirshfeld analysis, the Cl … H (29.2%), H … C (13.6%), and C … C (3.7%) contacts are the most important in the molecular packing of [Mn(L2)Cl2]n complex. The ligand L2 has better antibacterial, antifungal, and antioxidant activities than the Mn(II) complex. The [Mn(L2)Cl2]n complex has higher cytotoxic effect than L2 against both lung carcinoma A‐549 and lung fibroblast MRC‐5 cell lines. The IC50 and CC50 values of the Mn(II) complex are 26.09 ± 1.76 and 60.40 ± 3.74 μg ml−1, respectively, while 121.23 ± 5.91 and 241.13 ± 13.29 μg ml−1, respectively, for L2.