The reaction of potentially N,N,O-tridentate Schiff base ligands, Cl-LH, Br-LH, BrCl-LH and H-LH, with [V^IVO(acac)₂] in 2:1 ratio in methanol gave the corresponding mononuclear and dinuclear oxidovanadium(IV) complexes, VO(Cl-L)₂ (1), VO(Br-L)₂ (2), [(BrCl-L)₂(H₂O)V(μ-O)VO(BrCl-L)₂] (3) and [(H-L)₂(H₂O)V(μ -O)VO(H-L)₂] (4), in good yields. The ligands and complexes were fully characterized by elemental analysis and FT-IR spectroscopy. The ligands were also characterized by ¹H NMR spectroscopy. The oxidation state of V(IV)O with d¹ configuration in all synthesized complexes was confirmed by EPR. Moreover, the structures of 2 and 3 were determined by X-ray diffraction (XRD) analysis which revealed them as mono- and dinuclear vanadium(IV) complexes, respectively, with the ligands coordinated as bidentate chelates. The structure of 3 represents the first example of dinuclear V(IV) complex with O → V^IV = O → V^IV = O core (Cambridge Structural Database (CSD)​, version 5.42, update of May 2021). The cytotoxicity of ligands and complexes was evaluated towards ovarian (A2780), breast (MCF7) and prostate (PC3) cancer cells at 48 h. While ligands showed modest IC₅₀ values (>42 μM), all complexes turned out to be effective in the range 3.9–17.2 μM. In particular, A2780 and MCF7 cell lines were the most sensitive to the newly synthesized V(IV)O complexes.

潜在的 N,N,O-三齿希夫碱配体 Cl-LH、Br-LH、BrCl-LH 和 H-LH 与 [V ^IV O(acac) ₂ ] 以 2:1 的比例在甲醇中反应得到相应的单核和双核氧化钒(IV)配合物，VO(Cl-L) ₂ (1), VO(Br-L) ₂ (2), [(BrCl-L) ₂ (H ₂ O)V(μ-O) VO(BrCl-L) ₂ ] (3) 和 [(HL) ₂ (H ₂ O)V(μ -O)VO(HL) ₂ ] (4)，产率良好。通过元素分析和 FT-IR 光谱对配体和配合物进行了充分表征。配体还通过¹ H NMR 光谱表征。V(IV)O 与 d ¹的氧化态EPR 证实了所有合成复合物中的构型。此外，通过 X 射线衍射 (XRD) 分析确定了 2 和 3 的结构，表明它们分别为单核和双核钒 (IV) 配合物，配位体以双齿螯合物的形式配位。3 的结构代表了具有 O → V ^IV  = O → V ^IV  = O 核的双核 V(IV) 复合物的第一个例子（剑桥结构数据库 (CSD)，版本 5.42，2021 年 5 月更新）。在 48 小时时评估配体和复合物对卵巢 (A2780)、乳腺癌 (MCF7) 和前列腺 (PC3) 癌细胞的细胞毒性。虽然配体显示出适度的 IC ₅₀值 (>42 μM)，结果证明所有复合物在 3.9–17.2 μM 范围内都有效。特别是 A2780 和 MCF7 细胞系对新合成的 V(IV)O 复合物最敏感。