title: NMR and theoretical study on interactions between diperoxovanadate complex and 4-substituted pyridines.
abstract: To understand the substituting group effects of organic ligands on the reaction equilibrium, the interactions between diperoxovanadate complex [OV(O2)2(D2O)]-/[OV(O2)2(HOD)](-) and a series of 4-substituted pyridines in solution were explored using 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-substituted pyridines is pyridine > isonicotinate > N-methyl isonicotinamide > methyl isonicotinate. The competitive coordination results in the formation of a series of new six-coordinated peroxovanadate species [OV(O2)2L](n-) (L = 4-substituted pyridines, n = 1 or 2). The results of density functional calculations provide a reasonable explanation on the relative reactivity of the 4-substituted pyridines. Solvation effects play an important role in these reactions.
authors.affiliation: Department of Physics, State Key Laboratory of Physical Chemistry of Solid Surface, Xiamen University, Xiamen 361005, China.
authors.forename: Xianyong
authors.initials: X
authors.lastname: Yu
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.forename: Birong
authors.initials: B
authors.lastname: Zeng
authors.forename: Pinggui
authors.initials: P
authors.lastname: Yi
authors.forename: Shuhui
authors.initials: S
authors.lastname: Cai
authors.forename: Zhong
authors.initials: Z
authors.lastname: Chen
mesh_terms: D006861:Hydrogen Peroxide / Q000737:chemistry; D007554:Isotopes; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D011725:Pyridines / Q000737:chemistry*; D014638:Vanadates / Q000737:chemistry*; D014639:Vanadium / Q000737:chemistry
chemical_list: D007554:Isotopes; D008024:Ligands; D011725:Pyridines; C069276:peroxovanadate; D014639:Vanadium; D014638:Vanadates; D006861:Hydrogen Peroxide; C023666:pyridine