Two new polynuclear complexes [Ni6(amox)6(Ì6-O)(Ì3-OH)2]Cl2‚6H2O and [Cu3(amox)3 (Ì3-OH) (Ì3-Cl)]ClO4 4H2O (amox-) anion of 4-amino-4-methyl-2-pentanone oxime) have been synthesized and characterized structurally and magnetically. The Ni (II) complex contains a novel Chinese-lantern-like Ni6 cage centered by an oxo ion. It contains the nearest octahedral Ni (II)‚‚‚Ni (II) separation (<2.8 Å) and exhibits strong antiferromagnetic properties. The Cu (II) complex has a cyclic trinuclear copper (II) core bridged by both Ì3-OH-and Ì3-Cl-ions. The magnetic susceptibilities of both antiferromagnetic complexes were fitted by using approximate models.

A hetero-bimetallic complex K [Mn(acacen)] 2 [W(CN)8]

The ability of the oxamidato group to transmit efficiently magnetic coupling has been well documented. [3] The oxamidato-bridged GdIII-CuII complexes have been investigated magnetically since the pioneering research by Gatteschi et al., who first found that the GdIII–CuII exchange is ferromagnetic. [4] Recently, a four-coordinate macrocyclic oxamido-CuII complex has been used as "the complex ligand" tosuccessfully construct polynuclear Cu6Nd2 complexes. [5] It is anticipated that the coordinated CuL group (L=1, 4, 8, 11-tetraazacyclotradecane-2,3-dione) could accept donor atoms

A series of carboxylate-bridged 4f-3d complexes Cat+ [Cu(nta)Cl]2Ln(H2O)4 (Cat+) Na+ or K+, Ln3+) Gd3+ or La3+, and nta3-) nitrilotriacetate) have been synthesized by self-assembly of CuCl2‚4H2O, H3nta, and LnCl3‚6H2O in the presence of stoichiometric amounts of CatOH. X-ray diffraction analysis revealed that these complexes are isostructural and have a novel layered structure. The Ln3+ ion is coordinated by nine oxygen atoms of four [Cu(nta)Cl]2- and four water molecules, while each [Cu(nta)Cl]2- anion connects two Ln3+ using carboxylate oxygen atoms giving rise to a rhombus-like layered structure. The alkaline metal ions Cat+ are situated between the layers and coordinated to the oxygen atoms of [Cu(nta)Cl]2-generating a quasi-three-dimensional network. Magnetic studies indicate the presence of apparent antiferromagnetic coupling between Cu (II) and Gd (III) in KCu2Gd and NaCu2Gd. The magnetic susceptibilities of KCu2-La were simulated by using a quadratic model, which suggests a weak antiferromagnetic Cu (II) -Cu (II) coupling.