title: Syntheses, structure, and magnetic properties of heteronuclear Cu(II)4Fe(III)4 cluster and Cu(II)8 bimetallacycles.
abstract: The compartmental Schiff base ligands N,N'-ethylenebis(3-hydroxysalicylidene) (H(4)L) and N,N'-propylenebis(3-hydroxysalicylidene) (H(4)L') have been employed in the synthesis of a cyclic tetranuclear Cu(II) complex [Cu(4)(L')(2)(MeOH)(3)(H(2)O)]·[Cu(4)(L')(2)(MeOH)(3)] (1), a novel octanuclear Cu(II) complex [Cu(8)(L-L)(2)(H(2)O)(4)(μ(2)-H(2)O)]·3DMF·3H(2)O (2) and a hetero-octanuclear Cu(II)-Fe(III) complex [Cu(4)Fe(4)(L)(4)(H(2)O)(3)(μ(3)-O)(2)]·3DMF·3H(2)O (3). During the formation of the Cu(8) complex (2), a new bis-Schiff base ligand (L-L)(8-) forms via the ortho-para C-C coupling of two H(4)L ligands. The bicyclic complex (2) is comprised of two cyclic Cu(4) units that are similar to that of complex 1. In the Cu(4) unit, the alternate Cu(II) ions are singly bridged by phenoxo groups. The three complexes display overall antiferromagnetic coupling, and the Cu(II)-Cu(II) magnetic coupling constant falls in the range -117.2 to -473.6 cm(-1) for complexes 1 and 2 corresponding to the bridging Cu-O(phenoxide)-Cu bond angles of 124.3-131.0°.
authors.affiliation: Department of Chemistry, Tsinghua University, Beijing 100084, P. R. China.
authors.forename: Kong-Qiu
authors.initials: KQ
authors.lastname: Hu
authors.forename: Shu-Qi
authors.initials: SQ
authors.lastname: Wu
authors.forename: Guang-Yu
authors.initials: GY
authors.lastname: An
authors.forename: Ai-Li
authors.initials: AL
authors.lastname: Cui
authors.forename: Hui-Zhong
authors.initials: HZ
authors.lastname: Kou
mesh_terms: D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D018360:Crystallography, X-Ray; D005290:Ferric Compounds / Q000737:chemistry*; D008024:Ligands; D008280:Magnetics; D008968:Molecular Conformation; D012545:Schiff Bases
chemical_list: D056831:Coordination Complexes; D005290:Ferric Compounds; D008024:Ligands; D012545:Schiff Bases; D003300:Copper