Cobalt complexes of the chelating dicarboxylate ligand "esp": a paddlewheel-type dimer and a heptanuclear coordination cluster.

The coordination chemistry of Co(II) with the chelating dicarboxylate ligand esp (esp = α,α,α’,α’-tetramethyl-1,3-benzenedipropionate) is explored. We report here the bimetallic paddlewheel-type dimer, Co2(esp)2(EtOH)2 (1), and a bowl-shaped, heptanuclear coordination cluster, Co7(OH)4(Hesp)2(esp)4(MeCN)24MeCN (2). Crystal structures of both complexes are reported as well as their magnetic properties, which indicate antiferromagnetic interactions among the Co(II) ions. Reaction of cobalt carbonate with α,α,α’,α’-tetramethyl-1,3-benzenedipropionic acid (H2esp) in ethanol forms the paddlewheel-type dimer Co2(esp)2(EtOH)2, which hydrolyzes in acetonitrile solution to give a bowl-shaped heptacobalt coordination cluster complex; both compounds display antiferromagnetic interactions between high-spin Co(II) ions.

本文探究了Co(II)与螯合二羧酸配体esp（esp = α,α,α’,α’ - 四甲基 - 1,3 - 苯二丙酸根）的配位化学。在此，我们报道了双金属桨轮型二聚体Co₂(esp)₂(EtOH)₂（1）以及一种碗状的七核配位簇合物Co₇(OH)₄(Hesp)₂(esp)₄(MeCN)₂·4MeCN（2）。文中给出了这两种配合物的晶体结构及其磁学性质，结果表明Co(II)离子之间存在反铁磁相互作用。 碳酸钴与α,α,α’,α’ - 四甲基 - 1,3 - 苯二丙酸（H₂esp）在乙醇中反应生成桨轮型二聚体Co₂(esp)₂(EtOH)₂，该二聚体在乙腈溶液中水解，得到一种碗状的七钴配位簇合物；这两种化合物中的高自旋Co(II)离子之间均表现出反铁磁相互作用。