The Chemistry of Novel Highly Oxidized Middle Transition Metal Complexes

无机、生物无机和有机金属项目的这一奖项授予卡内基梅隆大学化学系的特伦斯·J·柯林斯博士，以继续研究含有高氧化态过渡金属的配位化合物。柯林斯已经开发出不容易氧化的大分子酰胺配体，并可用于在异常高的氧化状态下保持锰、铁、钴和镍。将尝试合成更多这种类型的化合物。根据不同金属和化合物的结构，它可以作为甲烷单加氧酶的模型，作为电催化剂或化学传感器，催化氧原子转移，或在低温下表现出反铁磁耦合。这些化合物将使用各种技术进行表征，包括电子顺磁共振和穆斯堡尔谱以及循环伏安法。研究将集中在已知的四个方形平面的Mn(V)络合物，以及五和六个坐标系。将尝试合成一些已知的锰和铁化合物的硝基类似物。还将研究Fe(IV)、Ni(III)和Co(III)的氧原子转移反应。我们将详细探讨一种稳定的Fe(IV)-O-Fe(IV)物种的反应化学，该物种已知经历了三次可逆氧化。对具有反铁磁耦合的S=2Mn(III)中心的线性聚合物进行了详细的磁学研究，该聚合物在低温下显示出异常的铁磁相互作用。

This award in the Inorganic, Bioinorganic, and Organometallic program is made to Dr. Terrence J. Collins in the Chemistry Department of Carnegie Mellon University to continue work on coordination complexes containing transition metals in high oxidation states. Collins has developed macroamide ligands which are not susceptible to oxidation and can be used to maintain Mn, Fe, Co, and Ni in unusual high oxidation states. Synthesis of additional compounds of this type will be attempted. Depending on the metal and structure of the respective compound, it may serve as a model for methane monooxygenase, as an electrocatalyst or chemical sensor, a catalytic O-atom transfer agent, or exhibit antiferromagnetic coupling at low temperatures. The compounds will be characterized using a variety of techniques, including electron paramagnetic resonance and Mossbauer spectroscopies, and cyclic voltammetry. The investigation will focus on four square-planar complexes of Mn(V) that are known, as well as 5- and 6-coordinate systems. Synthesis of nitrido analogs of some known manganese and iron compounds will be attempted. Oxygen atom transfer reactions of Fe(IV), Ni(III), and Co(III) will also be investigated. The reaction chemistry of a stable Fe(IV)-O-Fe(IV) species, which is known to undergo three reversible oxidations, will be explored in detail. A detailed magnetic study will be undertaken of a linear polymer of antiferromagnetically coupled S=2 Mn(III) centers that shows unusual ferromagnetic interactions at low temperatures.