Synthesis, crystal structure and properties of the dimeric copper(II) complex, [Cu-2(Hboa)(2)(H2O)(2)]center dot(ClO4)(2) (H(2)boa = biacetyl oxime azine)

The crystal structure of the polyhydrazone dioxime-containing dimeric coppe r(II) (polyhydrazone dioxime: HON=CMe[CMe=NN=CMe](n)CMe=NOH) complex, [Cu-2 (Hboa)(2)(H2O)(2)] . (ClO4)(2) (1) (H(2)boa = biacetyl oxime azine) has bee n determined. Complex (1) contains an unusual six-membered ring, which is c omposed of two oxime groups and two Cu-II ions. The variable temperature ma gnetic susceptibility of (1) in the 5-300 K range has been interpreted in t erms of a Cu-II dimer. The magnetic behavior shows that the bridging six-me mbered ring mediates very strongly in the antiferromagnetic exchange intera ction, with the fitting value J = -361(1) cm(-1) and the e.p.r. g-value of 2.193.