A series of new diiron azadithiolate (ADT) complexes (1–8), which could be regarded as the active site models of [FeFe]hydrogenases, have been synthesized starting from parent complex [(μ-SCH2)2NCH2CH2OH]Fe2(CO)6 (A). Treatment of A with ethyl malonyl chloride or malonyl dichloride in the presence of pyridine afforded the malonyl-containing complexes [(μ-SCH2)2NCH2CH2O2CCH2CO2Et]Fe2(CO)6 (1) and [Fe2(CO)6(μ-SCH2)2NCH2CH2O2C]2CH2 (2). Further treatment of 1 and 2 with PPh3 under different conditions produced the PPh3-substituted complexes [(μ-SCH2)2NCH2CH2O2CCH2CO2Et]Fe2(CO)5(PPh3) (3), [(μ-SCH2)2NCH2CH2O2CCH2CO2Et]Fe2(CO)4(PPh3)2 (4), and [Fe2(CO)5(PPh3)(μ-SCH2)2NCH2CH2O2C]2CH2 (5). More interestingly, complexes 1–3 could react with C60 in the presence of CBr4 and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) via Bingel–Hirsch reaction to give the C60-containing complexes [(μ-SCH2)2NCH2CH2O2CC(C60)CO2Et]Fe2(CO)6 (6), [Fe2(CO)6(μ-SCH2)2NCH2CH2O2C]2C(C60) (7), and [(μ-SCH2)2NCH2CH2O2CC(C60)CO2Et]Fe2(CO)5(PPh3) (8). The new ADT-type models 1–8 were characterized by elemental analysis and spectroscopy, whereas 2–4 were further studied by X-ray crystallography and 6–8 investigated in detail by DFT methods.
从母体[(μ-SCH2)2NCH2CH2OH]Fe2(CO)6(A)开始,合成了一系列新的
叠氮二
硫酸盐二
铁(ADT)配合物(1-8),它们可被视为[FeFe]氢化酶的活性位点模型。在
吡啶存在下,用
丙二酰氯或
丙二酰氯处理 A,可得到含
丙二酰氯的络合物 [(μ-SCH2)2NCH2CH2O2CCH2CO2Et]Fe2(CO)6(1)和 [Fe2(CO)6(μ-SCH2)2NCH2CH2O2C]2CH2(2)。在不同条件下,用 PPh3 进一步处理 1 和 2,可生成 PPh3 取代的络合物 [(μ-SCH2)2NCH2CH2O2CCH2CO2Et]Fe2(CO)5(PPh3)(3)、(μ-SCH2)2NCH2CH2O2CCH2CO2Et]Fe2(CO)4(PPh3)2(4)和[Fe2(CO)5(PPh3)(μ-SCH2)2NCH2CH2O2C]2CH2(5)。更有趣的是,配合物 1-3 在
CBr4 和 1,8- 二
氮杂双环[5.4.0]十一-7-烯(1,8-diazabicyclo[5.4.0]undec-7-ene)存在下能与 C60 反应。0]十一-7-烯(
DBU)通过宾格尔-赫希反应生成含 C60 的复合物[(μ-SCH2)2NCH2CH2O2CC(C60)CO2Et]Fe2(CO)6 (6)、[Fe2(CO)6(μ-SCH2)2NCH2CH2O2C]2C(C60)(7)和[(μ-SCH2)2NCH2CH2O2CC(C60)CO2Et]Fe2(CO)5(PPh3)(8)。新的 ADT 型模型 1-8 通过元素分析和光谱学进行了表征,而 2-4 则通过 X 射线晶体学进行了进一步研究,6-8 则通过 DFT 方法进行了详细研究。