NMR and theoretical study on the linking properties of peroxovanadium(V) complexes with the 2-acylpyridine derivatives

Abstract

To understand the substitution effects of 2-acylpyridine on the reaction equilibrium, the coordination interaction between a series of 2-acylpyridine derivatives and peroxovanadium(V) complex [OV(O₂)₂(D₂O)]⁻/[OV(O₂)₂(HOD)]⁻ in solution was explored by the combined use of multinuclear (¹H, ¹³C, and ⁵¹V) magnetic resonance, COSY, together with HSQC in 0.15 M NaCl ionic medium for mimicking the physiological conditions. Some direct NMR data are given for the first time. The relative reactivity among the 2-acylpyridine derivative ligands is 2-acetylpyridine (1) > 2-propionylpyridine (2) > 2-butyrylpyridine (4) > 2-isobutyrylpyridine (3). The competitive coordination results in the formation of a series of new seven-coordinate peroxovanadium species [OV(O₂)₂L]⁻ (L = 1, 2, 3, and 4). The results of density functional calculations indicated that the solvation effects play an important role in these reactions, providing a reasonable explanation on the relative reactivity of the 2-acylpyridine derivative.

Graphical abstract

Keywords:

• Peroxovanadium
• 2-acylpyridine derivatives
• solvation effect
• NMR
• DFT-calculation

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by Scientific Research Fund of Hunan Provincial Education Department (18A192), National Natural Science Foundation of China (21671063).