Diphenylphosphino- or Dicyclohexylphosphino-Tethered Boryl Pincer Ligands: Syntheses of PBP Iridium(III) Complexes and Their Conversion to Iridium−Ethylene Complexes
Diphenylphosphino- or Dicyclohexylphosphino-Tethered Boryl Pincer Ligands: Syntheses of PBP Iridium(III) Complexes and Their Conversion to Iridium−Ethylene Complexes
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DOI：
10.1021/om9006455
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发表时间：
2009-10
期刊：
影响因子：
2.8
通讯作者：
Yasutomo Segawa;M. Yamashita;K. Nozaki
中科院分区：
文献类型：
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作者：
Yasutomo Segawa;M. Yamashita;K. Nozaki
合成了磷原子上含苯基或环己基的PBP钳形配体的两种氢化硼烷前驱体(1b，c)，并研究了它们与Ir的配位反应。含苯基的氢化硼烷1b与Ir[P(p-tol)3]2(CO)Cl反应生成18电子络合物[PhPBP]Ir(H)(CO)Cl(3b)，而与其他Ir(I)源反应得到复杂的混合物。在理论计算的基础上，与文献报道的TbU-PBP衍生物3a相比，讨论了3b的特征红外吸收峰。环己基取代氢硼烷1c与[Ir(C2H4)2Cl2]2形成16电子络合物[CyPBP]Ir(H)Cl(2c)。2c的X射线结构和计算研究表明，氢化物配体[B−H=1.9(5)A]接近于硼原子。2c与LiTMP(TMP=2，2，6，6-四甲基吡啶)在乙烯气氛下反应生成了单价Ir配合物[CyPBP]Ir(C2H4)(4c)，反应步骤与文献报道的[tBuPBP]体系类似。实验..。
Two hydroborane precursors (1b,c) for PBP pincer ligands bearing phenyl or cyclohexyl groups on phosphorus atoms were synthesized, and their complexation reactions with iridium were investigated. Reaction of hydroborane 1b, bearing phenyl groups, with Ir[P(p-tol)3]2(CO)Cl afforded an 18-electron complex, [PhPBP]Ir(H)(CO)Cl (3b), but reactions with other iridium(I) sources gave complicated mixtures. The characteristic IR peaks in 3b compared with the previously reported tBu-PBP derivative 3a were discussed on the basis of theoretical calculations. Complexation of cyclohexyl-substituted hydroborane 1c with [Ir(C2H4)2Cl]2 afforded a 16-electron complex, [CyPBP]Ir(H)Cl (2c). X-ray structure and computational studies on 2c revealed that the hydride ligand is close [B−H = 1.90(5) A] to the boron atom. Reaction of 2c with LiTMP (TMP = 2,2,6,6-tetramethylpipyridide) under ethylene atmosphere gave monovalent iridium complex [CyPBP]Ir(C2H4) (4c) by a similar procedure to the previously reported [tBuPBP] system. Exp...