Abstract To understand the 4-substituting group effects of organic ligands in pyridine ring on the reaction equilibrium, the interactions between a series of 4-picoline-like ligands and [OV(O 2) 2(D 2O)] −/[OV(O 2) 2(HOD)] − in solution were explored by the combined use of multinuclear ( 1H, 13C, and 51V) magnetic resonance, DOSY, and variable-temperature NMR in 0.15 mol/L NaCl ionic medium for mimicking the physiological condition. Some direct NMR data are given for the first time. The reactivity among the 4-picoline-like ligands is 4-picoline > isonicotinate > isonicotinamide > ethyl isonicotinate. The competitive coordination results in the formation of a series of new six-coordinated peroxovanadate species [OV(O 2) 2L] n− (L = 4-picoline-like ligands, n = 1 or 2). The results of density functional calculations provide a reasonable explanation on the relative reactivity of the 4-picoline-like ligands. Solvation effects play an important role in these reactions.