ALKOXY-BRIDGED COMPLEXES OF COPPER(II) AND NICKEL(II) WITH SCHIFF-BASES OF ALCOHOLAMINES INCLUDING EFFECTS OF STRUCTURAL DISTORTION ON THE ELECTRONIC-SPECTRA OF 6-COORDINATE NICKEL(II) COMPLEXES

This paper describes the copper(II) complexes of the Schiff bases (eiLH2) of 2-aminoethanol with acetylacetone benzoylacetone, dibenzoylmethane and ethyl acetoacetate, together with the copper(II) complexes of the Sehiff bases _(piLH2) of 3-amino-l -propanolwith the above diones. Nickel(II) complexes are also described, using some eiLH2 Schiff bases incorporating the first three diones. Measurements of molecular weight, mass and visible spectra and magnetic measurements down to ca. 9OK, are reported. The complexes [Cu(eiL)]4 appear to be tetrameric, probably with oxygen-bridged cubane structures; they have room temperature μeff values of ca. 1.9 B.M. and are weakly ferromagnetic. The complexes [Cu(piL)]2 and [Ni(eiL)]2 appear to have planar dimeric structures; the copper complexes have magnetic moments of ca. 0.6 B.M. and the nickel complexes are diamagnetic. Some paramagnetic alcohol adducts of the type [Ni(eiL)ROH]4(R = Me, Et, n-Pr, n-Bu ) are assigned tetrameric cubane structures. These alcoholate complexes have μeff values of ca. 3.3 B.M. at room temperature, and appear to be weakly ferromagnetic. The reflectance electronic spectra of the [Ni(eiL)ROH]4 complexes are unusual in that they give evidence of marked tetragonal distortion, which appears to be produced by a structural distortion in the coordination environment of the nickel(II) ions. These spectra are compared with those of other, less distorted, nickel(II) tetramers. © 1979.