Structural, Magnetic and IR Spectroscopic Characterization of Dimeric Copper(II) Trichloroacetate Adduct with Benzonitrile. Nature of the Copper(II)-Benzonitrile Bond

Article abstract of DOI:10.1246/bcsj.58.968

The benzonitrile adduct of copper(II) trichloroacetate, 2, was prepared and characterized.The dimeric structure was confirmed by an X-ray structural determination.This compound crystallizes in the triclinic space group P1<*> with a=12.780(1), b=16.064(1), c=10.130(1) Angstroem; α=108.39(1), β=113.34(1), γ=81.07(1) ^o.The crystal consists of two crystallographically independent dimeric units.Both units have the familiar dimeric copper(II) acetate monohydrate structure with Cu-Cu distances of 2.731(1) and 2.732(1) Angstroem.Magnetic susceptibility data in the range of 80-300 K are well represented by the usual dimer equation with a singlet-triplet energy separation of -2J=224 cm^-1.The C<*>N stretching frequency of benzonitrile in the compound shows an increase by 31 cm^-1 from the free ligand value.On the basis of the X-ray crystallographic and IR spectroscopic results, the nature of the copper(II)-benzonitrile bond is discussed.For discussion magnetic and spectroscopic properties of some analogous nitrile adducts of copper(II) chloroacetates were also studied.