NMR study of the [VO(O 2) 2F] 2− ion in solution: Synthesis, vibrational spectra and crystal structure of [NH 3CH 2CH 2NH 3][VO(O 2) 2F

Abstract

The presence of the [VO(O 2) 2F] 2− ion in an aqueous solution gives rise to a doublet ( δ = −714 ppm, J VF = 163 ± 3 Hz) in the 51V NMR, and a multiplet ( δ = −160 ppm, Δ ν 1/2 = 1163 Hz) in the 19F NMR spectrum. The formation of this species is enhanced in formamide solutions. The ethane-1,2-diammonium(2+) fluorooxodiperoxovanadate, [NH 3CH 2CH 2NH 3][VO(O 2) 2F], was prepared from aqueous solution and characterized by elemental analysis, and IR and Raman spectroscopies. The complex crystallizes in the orthorhombic space group Pbca with eight formula units in a cell of dimensions: a = 9.2690(4), b = 8.8321(5) and c = 16.7605(8) Å. The complex anion has a rare pentagonal pyramidal structure with a very weak intermolecular interaction d(V ⋯ O) = 2.8730(12) Å between the vanadium atom and the double-bonded oxygen atom from the adjacent anion.