Nonemployed Simple Carboxylate Ions in Well-Investigated Areas of Heterometallic Carboxylate Cluster Chemistry: A New Family of {Cu<sup>II</sup><sub>4</sub>Ln<sup>III</sup><sub>8</sub>} Complexes Bearing <i>tert</i>-Butylacetate Bridging Ligands
收藏资源简介：
The first use of tert-butylacetate as bridging ligand in 3d/4f-metal cluster chemistry, in conjunction with the versatile chelate ligand pyridine-2,6-dimethanol, has afforded a new family of [Cu4Ln8(OH)6(NO3)2(O2CCH2But)16(pdm)4] clusters with unprecedented structures and slow magnetization relaxation for the {CuII4DyIII8} member. The molecular structure of representative complex 1 consists of a {CuII4GdIII8} cage-like cluster built from two {CuGd3} cubanes which are linked to each other and to two {CuGd} subunits on opposite sides through two η2:η2:η2:μ5 NO3– ions. The metal ions are additionally bridged by μ3-OH–, μ3-OR–, and μ-OR– groups to give an overall [Cu4Gd8(μ5-NO3)2(μ3-OH)6(μ3-OR)2(μ-OR)8]14+ core. Peripheral ligation about the core is provided by the N,O,O-chelating part of the pdm2– groups and, more impressively, by the oxygen atoms of 16 bridging ButCH2CO2– ligands; the latter are arranged into five classes, adopting a total of six different binding modes with the metal centers. The combined work demonstrates the ligating flexibility of tert-butylacetate ion and its usefulness in the synthesis of new 3d/4f-metal cluster compounds.
