Abstract: A novel Re(V)-Re(II) nitrosyl complex, [Re(O)2(pyz)
4][Re(NO)Br4(pyz)] (pyz = pyrazine) was prepared and characterized
by X-ray diffraction, elemental analysis, infrared and
ultraviolet-visible absorption spectra. This product is obtained
in the initial steps of the reaction of (NBu4)[Re(NO)Br4(EtOH)]
with pyrazine. Both, the cation and the anion are mononuclear
complexes. The Re(V) atom in the cation is six-coordinate with
four nitrogen atoms from pyrazine ligands, and two oxo ligands.
The Re(II) anion is also six-coordinate, with four bromide
ligands, a linear nitrosyl group and one nitrogen from pyrazine.
The spectroscopic studies are discussed and compared with
those already reported separately for the cation and the anion.
Supporting information: X-Ray (CIF file)