NMR study on the coordination of diperoxovanadium(V) complexes with 2-hydroxymethyl pyridine derivatives

abstractTo understand the substitution effects of 2-hydroxymethyl pyridine on the reaction equilibrium, the interactions between a series of 2-hydroxymethyl pyridine derivatives and diperoxovanadium(V) complex [OV(O2)2(D2O)]−/[OV(O2)2(HOD)]− in solution were explored by the combined use of multinuclear (1H, 13C, and 51V) magnetic resonance together with HSQC in 0.15 mol L−1 NaCl ionic medium for mimicking the physiological conditions. Some direct NMR data are given for the first time. The relative reactivity among the 2-hydroxymethyl pyridine ligands is 2-hydroxymethyl pyridine (1) > 2-methoxymethyl pyridine (2) > 2-ethoxymethyl pyridine (3) > 2-propoxymethyl pyridine (4). The competitive coordination results in the formation of a series of new seven-coordinate diperoxovanadium species [OV(O2)2L]– (L = 1, 2, 3, and 4). The results of density functional calculations indicated that steric effects play an important role in these reactions, providing a reasonable explanation on the relative reactivity of the ...