Synthesis, solid-state structure, magnetic properties and Mossbauer spectral studies of {Fe[HC(3,5-Me_2pz)_3](H_2O)_3}(BF_4)_2

摘要

The reaction of Fe(BF _4)_2.6H_2O and one equivalent of HC(3,5-Me_2Pz)J in acetonitrile leads to the formation of {Fe[HC(3,5- Me_2pz)_3](H_2O)_3}(BF_4)_2. The solution phase 1 H NMR spectrum is broad with chemical shifts ranging from 54 to -42 ppm, a range that is indicative of a paramagnetic high-spin complex. Magnetic moment measurements show that the complex is paramagnetic in the solid-state with JJeff = 4.89JJI. The solid-state structure shows the NJFeOJ central core is a distorted octahedron with N-Fe-N angles averagin~ 84.4° and O-Fe-O angles averaging 90.0°. The average Fe-N distance is 2.18 A and the average Fe-O bond distance is 2.12 A. Mossbauer spectra, obtained at 78 and 295 K, clearly reveal that this complex is high-spin at these temperatures with hyperfine parameters typical of a pseudooctahedral iron(II) complex.