レドックス活性なdpp-Bian配位子を含む電子欠損ガリウム・アルミニウム種の合成とε-カプロラクトン重合活性

Synthesis and ε-Caprolactone Polymerization Activity of Electron-Deficient Gallium and Aluminum Species Containing a Charged Redox-Active dpp-Bian Ligand.

• Vladimir A Dodonov
• Alexander G Morozov
• Roman V Rumyantsev
• Georgy K Fukin
• Alexandra A Skatova
• Peter W Roesky
• Igor L Fedushkin

抄録

レドックス活性なdpp-Bian配位子(dpp-Bian = 1,2-ビス[(2,6-ジイソプロピルフェニル)イミノ]アセナフテン)を含む電子欠損ガリウム及びアルミニウム中心種の合成について述べる。ジガラン[(dpp-Bian)Ga-Ga(dpp-Bian)]と[PhC][PF]またはAgPFとを反応させると、ポリオキシド化した種[(dpp-Bian)GaF]( )、[(dpp-Bian)H][PF]( )、[(dpp-Bian)GaF(OPF)]が得られた。ジガランとＢ（ＣＦ）との反応により、ｄｐｐ-Ｂｉａｎラジカルアニオンの電子不足ガリレン［（ｄｐｐ-Ｂｉａｎ）ＧａＢ（ＣＦ）］が生成した。ジガランをシアン化トシルで軟酸化すると、dpp-Bianラジカルアニオンを含む三核カチオン種[(dpp-Bian)Ga(Tos)Ga(Tos)Ga(dpp-Bian)][Ga(CN)]（）が得られた。また、［（ｄｐｐ-Ｂｉａｎ）ＡｌＥｔ］と１ｅｑｉｖの［ＰｈＣ］［Ｂ（ＣＦ）］とを反応させると、中性のｄｐｐ-Ｂｉａｎのカチオン錯体［（ｄｐｐ-Ｂｉａｎ）ＡｌＥｔ］［Ｂ（ＣＦ）］（）が得られた。一方、[(dpp-Bian)AlEt(EtO)]を1 equivの[PhC][B(CF)]で処理すると、dpp-Bianラジカルアニオンの化合物[(dpp-Bian)AlEt(EtO)][B(CF) ()が得られた。ジエチルアルミニウム誘導体［（ｄｐｐ-Ｂｉａｎ）ＡｌＥｔ］と１ｅｑｉｖのＢ（ＣＦ）とを反応させると、ラジカルアニオンのｄｐｐ-Ｂｉａｎ配位子を含むカチオン性錯体［｛（ｄｐｐ-Ｂｉａｎ）ＡｌＥｔ｝Ｆ］［ＥｔＢ（ＣＦ）］（）が得られた。化合物と-の分子構造は単結晶X線回折分析により決定した。化合物と-はε-カプロラクトンの不死開環重合の活性な開始剤であることがわかった。

The synthesis of electron-deficient gallium- and aluminum-centered species containing a redox-active dpp-Bian ligand (dpp-Bian = 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene) is described. The reaction of digallane [(dpp-Bian)Ga-Ga(dpp-Bian)] with [PhC][PF] or AgPF resulted in polyoxidized species [(dpp-Bian)GaF] (), [(dpp-Bian)H][PF] (), and [(dpp-Bian)GaF(OPF)] (). The reaction of digallane with B(CF) led to electron-deficient gallylene [(dpp-Bian)GaB(CF)] of a dpp-Bian radical anion. The soft oxidation of digallane with tosyl cyanide gave the trinuclear cationic species [(dpp-Bian)Ga(Tos)Ga(Tos)Ga(dpp-Bian)][Ga(CN)] () containing dpp-Bian radical anions. The reaction of [(dpp-Bian)AlEt] with 1 equiv of [PhC][B(CF)] resulted in the cationic complex [(dpp-Bian)AlEt][B(CF)] () of neutral dpp-Bian, while the treatment of [(dpp-Bian)AlEt(EtO)] with 1 equiv of [PhC][B(CF)] resulted in the compound [(dpp-Bian)AlEt(EtO)][B(CF)] () of a dpp-Bian radical anion. The reaction of diethylaluminum derivative [(dpp-Bian)AlEt] with 1 equiv of B(CF) gave the cationic complex [{(dpp-Bian)AlEt}F][EtB(CF)] () containing radical-anion dpp-Bian ligands. The paramagnetic compounds , , , , , and were characterized by electron paramagnetic resonance spectroscopy, and the diamagnetic complex was characterized by NMR spectroscopy. The molecular structures of - and were established by single-crystal X-ray diffraction analysis. Compounds and - were found to be active initiators for immortal ring-opening polymerization of ε-caprolactone.