HIGHLY STABILIZED COPPER(III) COMPLEXES
HIGHLY STABILIZED COPPER(III) COMPLEXES
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DOI：
10.1021/ja00244a020
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发表时间：
1987-05-13
影响因子：
15
通讯作者：
TRECO, BGRT
中科院分区：
文献类型：
--
作者：
ANSON, FC;COLLINS, TJ;TRECO, BGRT
通过使用含有有机N-氨基和氧化物给体的强给体聚阴离子螯合（PAC）配体，可以合成一类稀有+ III氧化态的铜配合物。一个实例[PPh 4][Cu（π 4 -4）]的X射线晶体结构。2 H2O（H44 = 1，2-双（2-羟基-2-甲基丙酰胺基）苯）。金属中心被发现在一个正方形平面的环境与正常的键的距离和角度的铜（III）配方。铜（III/II）对对配体环境高度敏感。这个属性被利用来评估一系列的PAC配体，包含芳香族基团的相对供体的性能被认为是，并介绍了一种方法，用于确定最好的正式氧化态分配的金属中心在潜在的模棱两可的情况下。PAC配体的芳族基团被脂肪族基团取代的正式电位的趋势表明，每个铜（II）络合物的氧化是金属为中心的。铜（III/II）对的形式电位在大于1.1 V的范围内变化（相对于Fc+/Fc为-1.08至+0.14 V）。烷氧基配体是比酚氧基配体强得多的给体。更多的捐助PAC配体的铜（III）络合物是相当更稳定（更负的形式电位的铜（III/II）对）比迄今已观察到的第一行供体互补物的络合物。
It has been possible to synthesize a family of copper complexes in the rare + III oxidation state by employing strongly donating polyanionic chelating (PAC) ligands containng organic N-amido and oxido donors. The X-ray crystal structure of one example, [PPh4][Cu(.pi.4-4)] .cntdot. 2H2O (H44 = 1,2-bis(2-hydroxy-2-methylpropanamido)benzene), is reported. The metal center is found in a square-planar environment with normal bond distances and angles for the copper(III) formulation. Copper(III/II) couples are highly sensitive to ligand environments. This property is exploited to assess the relative donor properties of a series of PAC ligands that contain aromatic groups is considered, and an approach for determining the best formal oxidation state assignments for the metal centers in potentially ambiguous cases is introduced. The trend in formal potentials as the aromatic groups of the PAC ligands are replaced by aliphatic groups indicates that oxidation of each copper(II) complex is metal-centered. The formal potentials of the copper(III/II) couples vary over a range of more than 1.1 V (-1.08 to +0.14 V vs. Fc+/Fc). Alkoxide ligands are much stronger donors than phenoxide ligands. The copper(III) complexes of the more donating PAC ligands are considerably more stabilized (more negative formal potentials for copper(III/II) couples) than has been observed hitherto for complexes with first-row donor complements.