Mono- and Dinuclear Ag(I), Au(I), and Au(III) Metallamacrocycles Containing N-Heterocyclic Dicarbene Ligands
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- 作者：Juan Gil-Rubio ; Ver贸nica C谩mara ; Delia Bautista ; Jos茅 Vicente
- 刊名：Inorganic Chemistry
- 出版年：2013
- 出版时间：April 1, 2013
- 年：2013
- 卷：52
- 期：7
- 页码：4071-4083
- 全文大小：708K
- 年卷期：v.52,no.7(April 1, 2013)
- ISSN：1520-510X
文摘
Ag(I) dicarbene complexes [Agm(Ln)m]Xm (Ln = ImMe(CH2)nImMe, ImMe = N-methylimidazol-N-yl-2-ylidene; n = 3, X = PF6, m = 2; n = 6鈥?, 10, X = AgBr2, m = 1, 2) were prepared by reacting Ag2O with 1 equiv of the corresponding bisimidazolium salt [H2Ln]A2 (A = PF6, Br). The dibromoargentates react with 1 equiv of AgTfO to afford [Agm(Ln)m](TfO)m (m = 1, 2). The room temperature transmetalation reaction of [Agm(Ln)m][AgBr2]m (n = 3, 5, 6鈥?, 10) with [AuCl(SMe2)] and AgTfO (Ln:Au:TfO = 1:1:1) affords [Au2(渭-Ln)2](TfO)2 (n = 3, 5, 10), or mixtures of [Au(魏2-Ln)]TfO (main product for n = 7) and [Au2(渭-Ln)2](TfO)2 (main product for n = 6, 8). At room temperature, the equilibrium between [M2(渭-Ln)2](TfO)2 and [M(魏2-Ln)]TfO is fast for M = Ag, but slow for M = Au, in the NMR time scale. When n 鈮?7 and M = Ag or Au, the equilibrium is shifted toward the mononuclear complexes in the order 8 > 10 > 7, which proves that the (CH2)8 linker has the optimal length for trans chelation. Correspondingly, the high-temperature metalation of [H2Ln]Br2 (n = 8, 10) with 1 equiv of [AuCl(SMe2)] and excess of NaAcO, affords [Au(魏2-Ln)]Br with a small amount of [Au2(渭-Ln)2]Br2. If AgTfO is added to the reaction mixture, [Au(魏2-L8)]2[AgBr3] is isolated instead of the desired triflate, which can be obtained by reacting the mixture of [Au(魏2-L8)]Br and [Au2(渭-L8)2]Br2 with AgTfO. [Au(魏2-L10)]TfO was isolated after thermal conversion of [Au2(渭-L10)2](TfO)2. [Au(魏2-L8)]TfO reacts with I2 to give trans-[AuI2(魏2-L8)]TfO, which is the first Au(III) complex containing a trans-spanning bidentate ligand. We have determined the crystal structures of complexes [Ag2(渭-L3)2](PF6)2, [Ag(魏2-L7)]TfO, [Au2(渭-L3)2](TfO)2, [Au(魏2-L8)]Br, [Au(魏2-L8)]2[AgBr3], and trans-[AuI2(魏2-L8)]TfO.