Characterization of metal complexes of 2,6-diacetylpyridinebis(imines). Preparation and crystal structure of tetrafluoroborato-2,2'-bipyridylpyridine>copper(II) tetrafluoroborate

Article abstract of DOI:10.1007/BF01171055

X-ray analysis has established the semicoordination bonding mode for one tetrafluoroborate anion in tetrafluoroborato-2,2'-bipyridyl<2,6-bis<1-(p-ethylphenylimino)ethyl>pyridine>copper(II) tetrafluoroborate, BF4.Crystals of the title compound are monoclinic, space group P2₁/n with four molecules in the unit cell of a = 14.991(3), b = 14.989(3), c = 16.933(4) Angstroem, β = 109.33(2) deg.The structure was solved by the heavy-atom method and refined by blocked full-matrix least squares calculations with anisotropic thermal parameters for nonhydrogen atoms to R = 0.049 and R_w = 0.051 for 3311 reflections with I > 3?(I).The copper atom coordination is pseudo-octahedral, with one nitrogen atom of the bipyridyl ligand and three nitrogen atoms of the terdentate NNN donor ligand forming the equatorial plane.The axial sites are occupied by the second nitrogen atom of the bipyridyl ligand and a loosely bound fluorine atom of the semicoordinated tetrafluoroborate group.The other BF4^- anion os ionic.Electronic and vibrational spectral data for the complex are discussed in terms of the geometry of the cation.