NMR study of the [VO(O2)2F]2- ion in solution:: Synthesis, vibrational spectra and crystal structure of [NH3CH2CH2NH3][VO(O2)2F]

The presence of the [VO(O-2)(2)F](2-) ion in an aqueous solution gives rise to a doublet (delta = -714 ppm, J(VF) = 163 +/- 3 Hz) in the V-51 NMR, and a multiplet (delta = - 160 ppm, A nu(1/2) = 1163 Hz) in the F-19 NMR spectrum. The formation of this species is enhanced in formamide solutions. The ethane-1,2-diammonium(2+). fluorooxodiperoxovanadate, [NH3CH2CH2NH3][VO(O-2)(2)F], 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) angstrom. The complex anion has a rare pentagonal pyramidal structure with a very weak intermolecular interaction d((VO)-O-...) = 2.8730(12) angstrom between the vanadium atom and the double-bonded oxygen atom from the adjacent anion. (c) 2005 Elsevier B.V. All rights reserved.