Crystal structure of bis(acetato-κ¹O)-bis methanol-κ¹O)bis(1-(4-chlorophenoxy)-3,3-dimethyl-1-(1H-1,2,4-triazol-1-yl)butan-2-ol-κ¹N)nickel(II)

1 Source of material

The compound 1-(4-chlorophenoxy)-3,3-dimethyl-1-(1H-1,2,4-triazol-1-yl) butan-2-ol (0.2958 g, 1.00 mmol) was dissolved in methanol (10 mL). To this solution was added nickel(II) acetate tetrahydrate (0.1244 g, 0.5 mmol). The mixture was stirred at room temperature for 2 h; blue block crystals of the target complex were subsequently obtained by slow evaporation of the solvent from ethanol.

2 Experimental details

Hydrogen atoms were placed in their geometrically idealized positions and constrained to ride on their parent atoms, with C–H = 0.96 Å (methyl), U_iso (H) = 1.5 U_eq(C), C–H = 0.98 Å (methine), U_iso(H) = 1.2 U_eq(C), C–H = 0.93 Å (aromatic and alkenyl), U_iso(H) = 1.2 U_eq(C), and O–H = 0.82 Å (hydroxyl), U_iso(H) = 1.5 U_eq(O).

3 Comment

Fungi are major causative agents of severe infectious diseases in plants worldwide, accounting for the most significant economic losses among crop pathogens. ^{6 , 7} To combat fungal infections, 1,2,4-triazole fungicides are widely employed. ⁸ However, their extensive use has led to the rapid development of resistant strains. ^{9 , 10} In an effort to improve bioactivity and mitigate resistance, strategies such as coordinating these fungicides with metal salts have been investigated. ^{11 , 12 , 13} Triadimenol (1-(4-chlorophenoxy)-3,3-dimethyl-1-(1H-1,2,4-triazol-1-yl)butan-2-ol) is a highly effective 1,2,4-triazole fungicide known for its low toxicity, limited residue, and sustained protective activity. It exhibits broad efficacy against powdery mildew, rust, leaf spots, and anthracnose. ¹³ This paper reports the synthesis and characterization of a novel Ni(II) complex derived from triadimenol.

As shown in the figure, the central Ni(II) ion adopts a six-coordinated octahedral geometry. The coordination sphere comprises two triadimenol ligands, each coordinated through a nitrogen atom (N) from the triazole ring; two coordinated methanol molecules, each bound via an oxygen atom; and two acetate ions, each acting as a monodentate ligand. The triazole rings are coplanar with their respective symmetry planes and are approximately perpendicular to the attached benzene rings, with a dihedral angle of 76.6°. The Ni–N bond length (2.073 Å) and Ni–O bond lengths (2.060 Å, 2.088 Å) are consistent with reported values for similar coordination bonds. ¹⁴ In the crystal structure, one type of intermolecular hydrogen bond is observed: atom O2 acts as a hydrogen bond donor to atom O3 of a symmetry-related molecule (symmetry code: (i) −x + 1, −y + 1, −z + 1), forming an O2–H2⋯O3 ⁱ interaction. These hydrogen bonds link the molecules into one-dimensional chains. Further stabilization of the crystal architecture is achieved through van der Waals interactions, which connect these chains into a three-dimensional framework.