Lionetti Davide, Day Michael W, Agapie Theodor
Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd. MC 127-72, Pasadena, CA 91125, USA.
Chem Sci. 2013 Jan 1;4(2):785-790. doi: 10.1039/C2SC21758A. Epub 2012 Nov 26.
A trinucleating framework was assmbled by templation of a heptadentate ligand around yttrium and lanthanides. The generated complexes orient three sets of two or three N-donors each for binding additional metal centers. Addition of three equivalents of copper(I) leads to the formation of tricopper(I) species. Reactions with dioxygen at low temperatures generate species whose spectroscopic features are consistent with a μ,μ-dioxo-tricopper complex. Reactivity studies were performed with a variety of substrates. The dioxo-tricopper species deprotonates weak acids, undergoes oxygen atom transfer with one equivalent of triphenylphosphine to yield triphenylphosphine oxide, and abstracts two hydrogen atom equivalents from tetramethylpiperidine-N-hydroxide (TEMPO-H). Thiophenols reduce the oxygenated species to a Cu complex and liberate two equivalents of disulfide, consistent with a four-electron four-proton process.
通过七齿配体围绕钇和镧系元素进行模板化组装了一个三核框架。生成的配合物将三组每组两个或三个氮供体定向排列以结合额外的金属中心。加入三当量的铜（I）会导致三铜（I）物种的形成。在低温下与氧气反应生成的物种，其光谱特征与μ,μ-二氧代-三铜配合物一致。使用多种底物进行了反应性研究。二氧代-三铜物种使弱酸去质子化，与一当量的三苯基膦进行氧原子转移生成三苯基膦氧化物，并从四甲基哌啶-N-氧化物（TEMPO-H）中夺取两当量的氢原子。硫酚将氧化态物种还原为铜配合物并释放两当量的二硫化物，这与四电子四质子过程一致。
