Sterically crowded triazenides as novel ancillary ligands in copper chemistry

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• 作者：Hyui Sul Lee^a ; Mark Niemeyer^b ; ^{niemeyer@uni-mainz.de"" rel=""nofollow}
• 关键词：Copper complexes ; Sterically crowded ligands ; t-Butylisonitrile ; Triazenido ligands ; Triphenylphosphane
• 刊名：Inorganica Chimica Acta
• 出版年：2011
• 出版时间：1 August 2011
• 年：2011
• 卷：374
• 期：1
• 页码：163-170
• 全文大小：855 K

文摘

We have synthesized copper salts MN₃RR′ derived from the biphenyl- or m-terphenyl-substituted triazenes Tph₂N₃H (1a) and Dmp(Tph)N₃H (1b) (Dmp = 2,6-Mes₂C₆H₃ with Mes = 2,4,6-Me₃C₆H₂; Tph = 2-TripC₆H₄ with Trip = 2,4,6-i-Pr₃C₆H₂). The homoleptic copper triazenide [CuN₃Tph₂] (2a) was obtained in high yield from the metallation of 1a with mesityl copper in n-heptane, while the complex [CuN₃(Dmp)Tph] (2b) was generated by the same method in situ only. Reaction of 2a with triphenylphosphane gave the 2:1 adduct [CuN₃Tph₂(PPh₃)₂] (3a), regardless of the used complex/donor ratio, while reaction of 2a or 2b with a stochiometric amount of t-butylisonitrile afforded the 1:1 adducts [Tph₂N₃CuCNtBu] (4a) and [Dmp(Tph)N₃CuCNtBu] (4b). All new compounds (except 2b) have been characterized by ¹H NMR, ¹³C NMR and IR spectroscopy, elemental analysis, melting point (not 2a), and X-ray crystallography. The IR spectroscopic examination of the ν(CN) stretch in the isonitrile adducts 4a and 4b revealed the weaker donor character of the supporting triazenido ligands compared to related β-diketiminato ligands.