State Key Laboratory for Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
State Key Laboratory for Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
J Inorg Biochem. 2020 Jul;208:111086. doi: 10.1016/j.jinorgbio.2020.111086. Epub 2020 Apr 23.
A series of monomeric α-hydroxycarboxylato oxovanadium(IV) complexes [VO(Hcit)(tpy)]·HO (1) (Hcit = citric acid, tpy = 2,2':6',2-terpyridine), [VO(glyc)(tpy)]·5.5HO (2) (Hglyc = glycolic acid) and [VO(α-hbut)(tpy)]·3HO (3) (α-Hhbut = α-hydroxybutyratic acid) have been obtained from the reactions of vanadyl sulfate with α-hydroxycarboxylates and terpyridine in acidic solutions. These complexes feature bidentate citrate, glycolate or α-hydroxybutyrate respectively. The ligand chelates to vanadium atom through α-hydroxy (in 1) or α-alkoxy (in 2 and 3) and α-carboxy groups, while β-carboxy groups of citrate in 1 are free to participate strong hydrogen bonds with neighboring citrate. With comparable chelation, 1 shares a similar V-O distance [2.168(1) Å] with that observed in FeV-cofactor [2.17 Å] [1]. Moreover, nitrosyl vanadium complexes [V(NO)(glyc)(tpy)]·3HO (4) and [V(NO)(α-hbut)(tpy)]·4HO (5) were obtained via reductions of synthetic solutions of 2 and 3 with hydroxylamine respectively. The terminal oxygen atoms were substituted by linear nitrosyl groups in 4 and 5. They were fully characterized by UV-vis, IR, EPR spectra, X-ray structural analyses and theoretical bond valence calculations.
一系列单体α-羟羧酸氧钒(IV)配合物[VO(Hcit)(tpy)]·HO(1)(Hcit=柠檬酸，tpy=2,2':6',2-三联吡啶)、[VO(glyc)(tpy)]·5.5HO(2)(Hglyc=甘醇酸)和[VO(α-hbut)(tpy)]·3HO(3)(α-Hhbut=α-羟基丁酸)是通过硫酸氧钒与α-羟羧酸和三吡啶在酸性溶液中的反应得到的。这些配合物分别具有双齿柠檬酸、甘醇酸或α-羟基丁酸配体。配体通过α-羟基(在 1 中)或α-烷氧基(在 2 和 3 中)和α-羧基与钒原子螯合，而 1 中柠檬酸的β-羧基则自由参与与相邻柠檬酸的强氢键。在可比的螯合作用下，1 与 FeV 辅因子[2.17 Å][1]中观察到的 V-O 距离[2.168(1) Å]相似。此外，通过分别用羟胺还原 2 和 3 的合成溶液，得到了硝酰基钒配合物[V(NO)(glyc)(tpy)]·3HO(4)和[V(NO)(α-hbut)(tpy)]·4HO(5)。在 4 和 5 中，末端氧原子被线性硝酰基取代。它们通过 UV-vis、IR、EPR 光谱、X 射线结构分析和理论键价计算得到了充分的表征。
