title: A Novel Pentadentate Coordination Mode for the Carbonato Bridge: Synthesis, Crystal Structure, and Magnetic Behavior of (&mgr;(3)-CO(3))[Ni(3)(Medpt)(3)(NCS)(4)], a New Trinuclear Nickel(II) Carbonato-Bridged Complex with Strong Antiferromagnetic Coupling.
abstract: The trinuclear complex (&mgr;(3)-CO(3))[Ni(3)(Medpt)(3)(NCS)(4)] was obtained by reaction of basic solutions of nickel(II), Medpt (bis(3aminopropyl)methylamine) and thiocyanate ligand with atmospheric CO(2) or by simple reaction with carbonate anion. (&mgr;(3)-CO(3))[Ni(3)(Medpt)(3)(NCS)(4)] crystallizes in the triclinic system, space group P&onemacr;, with a = 12.107(5) Å, b = 12.535(7) Å, c = 16.169(9) Å, alpha = 102.69(5) degrees, beta = 92.91(5) degrees, gamma = 118.01(4) degrees, Z = 2, and R = 0.043. The three nickel atoms are asymmetrically bridged by one pentadentate carbonato ligand, which shows a novel coordination mode. The (&mgr;(3)-CO(3))[Ni(3)(Medpt)(3)(NCS)(4)] compound shows a very strong antiferromagnetic coupling. Fit as irregular triangular arrangement gave J(1) = -88.4, J(2) = -57.7, and J(3) = -9.6 cm(-)(1), which is the strongest AF coupling observed to date for Ni(3) compounds. The magnetic behavior of the carbonato bridge is discussed.
authors.affiliation: Departament de Química Inorgànica, Universitat de Barcelona, Diagonal, 647, 08028-Barcelona, Spain, Departament de Cristal.lografia i Mineralogia, Universitat de Barcelona, Martí Franqués s/n, 08028-Barcelona, Spain, and Dipartamento di Chimica, Università degli Studi di Firenze, Via Maragliano 75-77, 50144-Firenze, Italy.
authors.forename: Albert
authors.initials: A
authors.lastname: Escuer
authors.forename: Ramon
authors.initials: R
authors.lastname: Vicente
authors.forename: Sujit B.
authors.initials: SB
authors.lastname: Kumar
authors.forename: Xavier
authors.initials: X
authors.lastname: Solans
authors.forename: Mercé
authors.initials: M
authors.lastname: Font-Bardía
authors.forename: Andrea
authors.initials: A
authors.lastname: Caneschi