Synthesis, Molecular Structure, and Catalytic Potential of the Tetrairon Complex [Fe<sub>4</sub>(<i>N</i><sub>3</sub><i>O</i><sub>2</sub>-L)<sub>4</sub>(μ-O)<sub>2</sub>]<sup>4+</sup> (L = 1-Carboxymethyl-4,7-dimethyl-1,4,7-triazacyclononane)
作者:Vladimir B. Romakh、Bruno Therrien、Georg Süss-Fink、Georgiy B. Shul'pin
DOI:10.1021/ic062207k
日期:2007.4.1
formic acid; the total turnover numbers attain 24 catalytic cycles within 4 h. To gain more insight into the catalytic process, the catalytic potential of 2 was also studied for the oxidation of higher alkanes, cycloalkanes, and isopropanol in acetonitrile, as well as in aqueous solution. The bond selectivities of the oxidation of linear and branched alkanes suggest a ferroxy radical pathway.
硫酸铁与1-羧甲基-4,7-二甲基-1,4,7-三氮杂环壬烷(L)和过氧化氢在乙醇水溶液中的反应产生棕色双核络合物,被认为是[Fe2(N3O-L)2(mu -O)(mu-OOCCH3)] +(1),将其在乙腈溶液中放置后转化为绿色四核配合物[Fe4(N3O2-L)4(mu-O)2] 4+(2)。[2] [PF6] 4.5MeCN的单晶X射线结构分析显示,2包含四个铁(III)中心,每个中心与三氮杂环壬烷配体的三个氮原子配位,并被一个氧代和两个氧代桥接羧基桥,这是一种从甲烷单加氧酶活性中心已知的结构特征。因此,发现配合物2用过氧化氢在水溶液中催化甲烷的氧化功能化,得到甲醇,氢过氧化甲基和甲酸;总周转次数在4小时内达到24个催化循环。为了更深入地了解催化过程,还研究了2的催化电势,可用于乙腈和水溶液中高级烷烃,环烷烃和异丙醇的氧化。直链和支链烷烃氧化的键选择性表明存在铁氧自由基途径。