Experimental and computational studies of two new mono- and dinuclear iridium complexes containing a Buchwald biphenyl phosphine ligand

详细信息	查看全文 | 推荐本文 |

• 作者：Lutz Dahlenburg ; Ralf Menzel ; Ralph Puchta ; Frank W. Heinemann
• 关键词：2-Di-t-butylphosphino-2′ ; -methylbiphenyl ; Iridium complexes ; Cyclometalation ; DFT calculations ; X-ray structure analysis
• 刊名：Inorganica Chimica Acta
• 出版年：2008
• 期刊代码：40_00201693
• 类别：ch
• 出版时间：27 June 2008
• 卷：361
• 期：9-10
• 页码：2623-2630
• 文件大小：299 K

摘要

The reaction of [(η⁴-1,5-C₈H₁₂)₂Ir₂(μ-Cl)₂] with 2-di-t-butylphosphino-2′-methylbiphenyl (t-Bu₂Pbiph^Me) in the presence of AgBF₄ afforded the dichlorido-bridged Ir–Ag complex [(η⁴-1,5-C₈H₁₂)Ir(μ-Cl)₂Ag(t-Bu₂Pbiph^Me)] (rong>1rong>) which was fully characterized by a single crystal X-ray diffraction study. Sequential treatment of the diiridium precursor first with the silver salt and then with the phosphine yielded cyclometalated [(η⁴-1,5-C₈H₁₂)Ir(t-Bu₂Pbiph^Me–H⁺)] (rong>2rong>). Detailed DFT calculations gave evidence that the phosphine ligand of rong>2rong> forms a strained four-membered iridaheterocycle through orthometalation rather than a sterically congested six-membered chelate structure through C–H activation on the remote phenyl ring. The phosphonium salt [t-Bu₂P(H)biph^Me]BF₄ was isolated as a by-product of the preparations of rong>1rong> and rong>2rong>; its crystal structure was determined.