Hong Sungjun, Hill Lyndal M R, Gupta Aalo K, Naab Benjamin D, Gilroy Joe B, Hicks Robin G, Cramer Christopher J, Tolman William B
Department of Chemistry, Center for Metals in Biocatalysis, and Supercomputing Institute, University of Minnesota, 207 Pleasant St. SE, Minneapolis, Minnesota 55455, USA.
Inorg Chem. 2009 May 18;48(10):4514-23. doi: 10.1021/ic9002466.
Copper(I) complexes of a diketiminate featuring CF(3) groups on the backbone and dimethylphenyl substituents (4) and a nitroformazan (5) were synthesized and shown by spectroscopy, X-ray crystallography, cyclic voltammetry, and theory to contain copper(I) sites electron-deficient relative to those supported by previously studied diketiminate complexes comprising alkyl or aryl backbone substituents. Despite their electron-poor nature, oxygenation of LCu(CH(3)CN) (L = 4 or 5) at room temperature yielded bis(hydroxo)dicopper(II) compounds and at -80 degrees C yielded bis(mu-oxo)dicopper complexes that were identified on the basis of UV-vis and resonance Raman spectroscopy, spectrophotometric titration results (2:1 Cu/O(2) ratio), electron paramagnetic resonance spectroscopy (silent), and density functional theory calculations. The bis(mu-oxo)dicopper complex supported by 5 exhibited unusual spectroscopic properties and decayed via a novel intermediate proposed to be a metallaverdazyl radical complex, findings that highlight the potential for the formazan ligand to exhibit "noninnocent" behavior.
合成了一种在主链上带有CF(3)基团和二甲基苯基取代基的二酮亚胺（4）与硝基亚甲胺（5）的铜（I）配合物，并通过光谱学、X射线晶体学、循环伏安法和理论证明，相对于先前研究的包含烷基或芳基主链取代基的二酮亚胺配合物所支持的铜（I）位点，这些配合物中的铜（I）位点电子不足。尽管它们具有贫电子性质，但LCu(CH(3)CN)（L = 4或5）在室温下氧化生成双（羟基）二铜（II）化合物，在-80℃下生成双（μ-氧）二铜配合物，这些配合物通过紫外可见光谱和共振拉曼光谱、分光光度滴定结果（铜/氧（2）比例为2:1）、电子顺磁共振光谱（无信号）和密度泛函理论计算得以鉴定。由5支持的双（μ-氧）二铜配合物表现出不寻常的光谱性质，并通过一种被认为是金属氮杂环自由基配合物的新型中间体衰变，这些发现突出了亚甲胺配体表现出“非无辜”行为的潜力。
