SYNTHESIS, STRUCTURES, AND MAGNETIC-PROPERTIES OF BINUCLEAR CARBOXYLATE COMPLEXES WITH NI-II AND NI-III ATOMS

The reaction of NiCl2. 6H(2)O with Me3CCOOH and KOH taken in a molar r atio of 1 : 2 : 2 in water afforded the nonanuclear antiferromagnetic complex 3CCOOH)(4)(mu(4)-O)(3)(mu(3)-OH)(3)(OOCCMe3)(12)], which appar ently contains Ni-II and Ni-III atoms. The complex was isolated by ext raction with CH2Cl2, benzene, or hexane. The reactions of this complex with pyridine bases (pyridine (Py), 3,4-lutidine (Lut), and nicorandi l (Nic)) gave the adducts L4Ni2(OOCCMe3)(2)(mu-OOCCMe3)(2)(mu-OH) (L = Py, Lut, or Nic, respectively). According to magnetic measurements, i ntramolecular ferromagnetic exchange interactions in these adducts are complemented by intermolecular antiferromagnetic interactions. Pyroly sis of the pyridine adduct in air or under an inert atmosphere in xyle ne yielded the antiferromagnetic complex Py2Ni2(Me3CCOOH)(2)(OOCCMe3)( 2)(mu-OOCCMe3)(2), which contains Ni-II atoms. The structures of ail t he complexes synthesized were established by X-ray diffraction analysi s. The electronic absorption spectra of these compounds are considered .