Atoyebi Adewole O, Brückner Christian
Department of Chemistry , University of Connecticut , Unit 3060 , Storrs , Connecticut 06269-3060 , United States.
Inorg Chem. 2019 Aug 5;58(15):9631-9642. doi: 10.1021/acs.inorgchem.9b00052. Epub 2019 Mar 14.
Building on a proof of concept study that showed the possibility of the mechanochemical insertion of some M(II) metals into -tetraphenylporphyrin using a ball mill as an alternative to traditional solution-based methods, we present here a detailed study of the influence of the many experimental variables on the reaction outcome performed in a planetary mill. Using primarily the mechanochemical zinc, copper, and magnesium insertion reactions, the scope and limits of the type of porphyrins (electron-rich or electron-poor -tetraarylporphyrins, synthetic or naturally occurring octaalkylporphyrins, and -triphenylcorrole) and metal ion sources suitable for this metal insertion modality were determined. We demonstrate the influence of the experimental metal insertion parameters, such as ball mill speed and reaction time, and investigated the often surprising roles of a variety of grinding agents. Also, the mechanochemical reaction conditions that remove zinc from a zinc porphyrin complex or exchange it for copper were studied. Using some standardized conditions, we also screened the feasibility of a number of other metal(II) insertion reactions (VO, Ni, Fe, Co, Ag, Cd, Pd, Pt, Pb). The underlying factors determining the rates of the insertion reactions were found to be complex and not always readily predictable. Some findings of fundamental significance for the mechanistic understanding of the mechanochemical insertion of metal ions into porphyrins are highlighted. Particularly the mechanochemical insertion of Mg(II) is a mild alternative to established solution methods. The work provides a baseline from which the practitioner may start to evaluate the mechanochemical metal insertion into porphyrins using a planetary ball mill.
基于一项概念验证研究，该研究表明使用球磨机作为传统溶液法的替代方法，可将一些M(II)金属机械化学插入到-四苯基卟啉中，我们在此展示了对行星式球磨机中许多实验变量对反应结果影响的详细研究。主要利用机械化学锌、铜和镁插入反应，确定了适用于这种金属插入方式的卟啉类型（富电子或贫电子-四芳基卟啉、合成或天然存在的八烷基卟啉以及-三苯基咕啉）和金属离子源的范围及局限性。我们展示了实验性金属插入参数（如球磨机速度和反应时间）的影响，并研究了各种研磨剂通常令人惊讶的作用。此外，还研究了从锌卟啉配合物中去除锌或将其换成铜的机械化学反应条件。使用一些标准化条件，我们还筛选了许多其他金属(II)插入反应（VO、Ni、Fe、Co、Ag、Cd、Pd、Pt、Pb）的可行性。发现决定插入反应速率的潜在因素很复杂，并不总是易于预测。强调了一些对金属离子机械化学插入卟啉的机理理解具有根本意义的发现。特别是Mg(II)的机械化学插入是现有溶液法的温和替代方法。这项工作提供了一个基线，从业者可据此开始评估使用行星式球磨机将金属机械化学插入卟啉的情况。
