One- and Two-Electron-Transfer Reactions of (dpp-Bian)Sm(dme)₃

The reduction of 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene (dpp-Bian) with an excess of samarium in 1,2-dimethoxyethane (dme) affords the SmII complex (dpp-Bian)Sm(dme)3 (1). The reaction of 1 with 0.5 mol equiv of 1,2-dibromostilbene proceeds with the formation of the dimeric SmIII complex [(dpp-Bian)SmBr(dme)]2 (2). Oxidation of both the metal and the dpp-Bian ligand takes place if 1 is reacted with equimolar amounts of 1,2-dibromostilbene or iodine, yielding the monomeric SmIII derivatives (dpp-Bian)SmBr2(dme) (3) and (dpp-Bian)SmI2(THF)2 (4; THF = tetrahydrofuran), respectively. The reaction of 1 with 0.5 mol equiv of iodine followed by 0.5 mol equiv of tetramethylthiuram disulfide gives the SmIII complex (dpp-Bian)SmI[SC(S)NMe2](dme) (5). Compound 4 and tBuOK react with the formation of the iodine-bridged dimer [(dpp-Bian)SmI(OtBu)(THF)]2 (6). Complexes 1 and 2 have been characterized by 1H NMR spectroscopy and complexes 2−6 by their molecular structures, which were determined by single-crystal X-ray diffraction.以过量钐在1,2-二甲氧基乙烷（1,2-dimethoxyethane，dme）中还原1,2-双[(2,6-二异丙基苯基)亚氨基]苊（1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene，dpp-Bian），制得二价钐配合物$(dpp-Bian)Sm(dme)_3$（1）。将配合物1与0.5摩尔当量的1,2-二溴二苯乙烯反应，可得到二聚型三价钐配合物$[(dpp-Bian)SmBr(dme)]_2$（2）。若将配合物1与等摩尔量的1,2-二溴二苯乙烯或碘反应，则金属中心与dpp-Bian配体均发生氧化，分别得到单聚型三价钐衍生物$(dpp-Bian)SmBr_2(dme)$（3）与$(dpp-Bian)SmI_2(THF)_2$（4；THF=四氢呋喃，tetrahydrofuran）。将配合物1先与0.5摩尔当量的碘反应，再加入0.5摩尔当量的四甲基秋兰姆二硫化物，可得到三价钐配合物$(dpp-Bian)SmI[SC(S)NMe_2](dme)$（5）。配合物4与叔丁醇钾（tBuOK）反应，生成碘桥联二聚体$[(dpp-Bian)SmI(OtBu)(THF)]_2$（6）。已通过核磁共振氢谱（¹H NMR）光谱法对配合物1和2进行表征，并通过单晶X射线衍射测定配合物2~6的分子结构。