Samarocene sandwich complexes with superbulky penta-arylcyclopentadienyl ligands have been prepared and were structurally characterized: [(4-EtC₆H₄)₅C₅]₂Sm (1) and [(4-iPrC₆H₄)₅C₅]₂Sm (2). Analogous to the previously reported synthesis of [(4-nBuC₆H₄)₅C₅]₂Sm, reaction of (DMAT)₂Sm·(THF)₂ (DMAT = 2-Me₂N-α-Me₃Si-benzyl) and the appropriate Ar₅C₅H ligand gave 1 (66% yield) and 2 (59% yield). In contrast to the high reactivity of Cp*₂Sm, complex 1 has been shown to be surprisingly stable toward reaction with a large variety of reagents. Even under forcing conditions, no reaction with N₂, CO, CO₂, pyrazine, trans-stilbene, pyridine, P₄, and benzophenone was observed. Complex 1 reacts with cuminil ArC(O)C(O)Ar (Ar = 4-iPrC₆H₄) to yield the Sm(III) sandwich complex [(4-EtC₆H₄)₅C₅]₂Sm[ArC(O)C(O)Ar] (3), which could be isolated in 83% yield as a dark-red crystalline material. Complex 2 reacts with oxygen in the presence of phenazine to yield the bimetallic Sm(III) complex [(4-iPrC₆H₄)₅C₅Sm(η¹-phenazine)]₂(μ:η²-η²-O₂)₂ (4) in 25% yield as dark-red crystals. The unusually high redox-stability of deca-arylsamarocenes originates from steric hindrance of the Sm metal center.

中文翻译：

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十甲芳基新茂铁：一种异常惰性的Sm（II）三明治复合物

制备了具有超大体积的五芳基环戊二烯基配体的mar新世三明治复合物，并对其结构进行了表征：[（4-EtC ₆ H ₄）₅ C ₅ ] ₂ Sm（1）和[（4- i PrC ₆ H ₄）₅ C ₅ ] ₂平方米（2）。与先前报道的[（4- n BuC ₆ H ₄）₅ C ₅ ] ₂ Sm的合成相似，（DMAT）₂ Sm·（THF）₂（DMAT = 2-Me₂ N-α-我₃硅-苄基）和适当的Ar ₅ Ç ₅ ħ配体，得到1（66％收率）和2（收率59％）。与Cp * ₂ Sm的高反应性相反，已显示出配合物1对与多种试剂的反应具有惊人的稳定性。即使在强迫条件下，也未观察到与N ₂，CO，CO ₂，吡嗪，反式二苯乙烯，吡啶，P ₄和二苯甲酮的反应。配合物1与异丙基ArC（O）C（O）Ar（Ar = 4- i PrC ₆ H ₄）生成Sm（III）夹心复合物[（4-EtC ₆ H ₄）₅ C ₅ ] ₂ Sm [ArC（O）C（O）Ar]（3），可以83％的产率将其分离为深红色结晶物质。复杂2间发生反应，在吩嗪的存在下，得到双金属钐（III）配合物[（4-氧我PRC ₆ ħ ₄）₅ Ç ₅钐（η ¹ -phenazine）] ₂（μ：η ² -η ² - O ₂）₂（4）的深红色晶体产率为25％。十芳基顺丁烯二茂铁化合物异常高的氧化还原稳定性源于Sm金属中心的位阻。