作者:Steffen Leuthäußer、Daniela Schwarz、Herbert Plenio
DOI:10.1002/chem.200700228
日期:2007.8.27
The electron-donating properties of N-heterocyclic carbenes ([N,N'-bis(2,6-dimethylphenyl)imidazol]-2-ylidene and the respective dihydro ligands) with 4,4'-R-substituted aryl rings (4,4'-R=NEt2, OC(12)H(25), Me, H, Br, S(4-tolyl), SO(4-tolyl), SO2(4-tolyl)) were studied. Twelve new N-heterocyclic carbene (NHC) ligands were synthesized as well as the respective iridium complexes [IrCl(cod)(NHC)] and
具有4,4'-R-取代的芳基环的N-杂环卡宾([N,N'-双(2,6-二甲基苯基)咪唑] -2-亚烷基和相应的二氢配体)的供电子性能(4 ,4'-R = NEt2,OC(12)H(25),Me,H,Br,S(4-tolyl),SO(4-tolyl),SO2(4-tolyl))。合成了十二个新的N-杂环卡宾(NHC)配体以及相应的铱配合物[IrCl(cod)(NHC)]和[IrCl(CO)2(NHC)]。循环伏安法(DeltaE1 / 2)和IR(nu(CO))可用于测量卡宾配体的给电子性。用吸电子取代基(4-R = -SO(2)Ar,DeltaE1 / 2 = + 0.92 V)修饰4位化合物,得到的NHC配体实际上具有与[IrCl(cod)的三烷基膦相同的给电子能力)(PCy3)](DeltaE1 / 2 = + 0.95 V),