title: New Metal Oxamates as Precursors of Low-Dimensional Heterobimetallics.
abstract: The goal of this work was to synthesize new molecular bricks which could be used as precursors of heterobimetallic low-dimensional compounds. Along this line, four compounds have been synthesized and structurally characterized, namely (NBu(4))(2)[Ni(Cl(2)opba)] (1), (NBu(4))(2)[Cu(Cl(2)opba)] (2), (NBu(4))(5)[Mn(Cl(2)opba)(DMSO)(2)](4) (3), and Cu(en)(2)[Mn(Cl(2)opba)(H(2)O)(2)](2).2DMSO (4), with Cl(2)opba = (4,5-dichloro-o-phenylene)bis(oxamato), NBu(4) = tetra-n-butylammonium, en = ethylenediamine, and DMSO = dimethyl sulfoxide. Compounds 1 and 2 are isostructural; they crystallize in the monoclinic system, space group C2/c, Z = 4, with a = 18.708(2) Å, b = 17.525(2) Å, c = 14.763(9) Å, and beta = 92.03(4) degrees for 1 and a = 18.928(2) Å, b = 17.634(2) Å, c = 14.704(9) Å, and beta = 92.38(3) degrees for 2. 3 crystallizes in the tetragonal system, space group P&fourmacr;2(1)c, Z = 2, with a = 26.295(10) Å and c = 12.342(7) Å. The structure shows a random occupation of the metal site by Mn(III) and Mn(II) ions in 3/4 and 1/4 ratios, respectively. 4 crystallizes in the triclinic system, space group P&onemacr;, Z = 1, with a = 7.066(7) Å, b = 11.844(1) Å, c = 14.292(5) Å, alpha = 105.64(2) degrees, beta = 97.67(5) degrees, and gamma = 102.13(3) degrees. The structure consists of Mn(III)Cu(II)Mn(III) trinuclear species, with Cu-O-Mn bridges involving oxygen atoms of the oxamato groups already linked to the metal atom. The magnetic properties of compounds 1-4 have been investigated and quantitatively interpreted. For 3, this magnetic investigation has been performed on a single crystal, which allows us to determine unambiguously the sign of the axial zero-field splitting parameter for the Mn(III) ion. The potentialities of these new molecular bricks have been discussed.
authors.affiliation: Laboratoire de Chimie du Solide et Inorganique Moléculaire, URA CNRS No. 1495, Université de Rennes I, 35042 Rennes, France, Laboratoire de Chimie du Solide Appliquée, Faculté des Sciences, Université Mohammed V, Rabat, Morocco, and Laboratoire des Sciences Moléculaires, Institut de Chimie de la Matière Condensée de Bordeaux, UPR CNRS No. 9048, 33608 Pessac, France.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Fettouhi
authors.forename: Lahcène
authors.initials: L
authors.lastname: Ouahab
authors.forename: Ali
authors.initials: A
authors.lastname: Boukhari
authors.forename: Olivier
authors.initials: O
authors.lastname: Cador
authors.forename: Corine
authors.initials: C
authors.lastname: Mathonière
authors.forename: Olivier
authors.initials: O
authors.lastname: Kahn