Synthesis and characterization of molybdenum oxo complexes of two tripodal ligands: reactivity studies of a functional model for molybdenum oxotransferases
作者:Anders Thapper、Axel Behrens、Jacob Fryxelius、Maria H. Johansson、Fabio Prestopino、Miklós Czaun、Dieter Rehder、Ebbe Nordlander
DOI:10.1039/b505180k
日期:——
Reaction of the tetradentate ligand N-(2-hydroxybenzyl)-N,N-bis(2-pyridylmethyl)amine (L–OH) with MoO2Cl2 in methanol in the presence of NaOMe and PF6− results in the formation of [MoO2(L–O)]PF6. Similarly, the reaction of N-(2-mercaptobenzyl)-N,N-bis(2-pyridylmethyl)amine (L–SH) with MoO2(acac)2 leads to the formation of [MoO2(L–S)]+. The dioxo-molybdenum complex [MoO2(L–O)]+ reacts with phosphines in methanol to afford phosphine oxides and an air-sensitive molybdenum complex, tentatively identified as [Mo(IV)O(L–O)(OCH3)]. The latter complex is capable of reducing biological oxygen donors such as DMSO or nitrate, thereby mimicking the activity of DMSO reductase and nitrate reductase. Reaction of [MoO2(L–O)]PF6 with PPh3 in other solvents than methanol leads to the formation of the Mo(V) dimer [(L–O)OMo(μ-O)MoO(L–O)](PF6)2. The crystal structures of [MoO2(L–O)]PF6 and the μ-oxo bridged dimer are presented.
四齿配体N-(2-羟基苄基)-N,N-bis(2-吡啶甲基)胺(L–OH)与MoO2Cl2在甲醇中,在NaOMe和PF6−的存在下反应,形成[MoO2(L–O)]PF6。类似地,N-(2-巯基苄基)-N,N-bis(2-吡啶甲基)胺(L–SH)与MoO2(acac)2的反应生成[MoO2(L–S)]⁺。二氧茂铝复合物[MoO2(L–O)]⁺在甲醇中与磷烯反应,生成磷烯氧化物和一个对空气敏感的铝复合物,暂时鉴定为[Mo(IV)O(L–O)(OCH3)]。后者复合物能够还原生物氧给体,如DMSO或硝酸盐,从而模拟DMSO还原酶和硝酸盐还原酶的活性。[MoO2(L–O)]PF6与PPh3在不同于甲醇的溶剂中反应形成Mo(V)二聚体[(L–O)OMo(μ-O)MoO(L–O)](PF6)2。提供了[MoO2(L–O)]PF6和μ-氧桥连二聚体的晶体结构。