isomer. These isomers interconvert by rotation about the IrPMe2Ph bond and at 45°C a sharp coalesced AB2C spectrum is obtained. In the low-temperature 1H NMR spectrum, the major chiral isomer shows non-equivalent ortho-protons, whereas the minor achiral isomer gives a single resonance for these protons. Related rotamers are observed for the PMePh2 complex but we could not obtain frozen-out spectra for [IrCl2(PMe3)4]+
摘要合成了阳离子d6-络合物[IrCl2(PMe3)3L] +,其中L = PMe3,PMe2Ph或PMePh2,反式-mer- [IrCl2(PMe3)3(PMe2Ph)]
ClO4的单晶X射线结构·测定CH 2 Cl 2;阳离子是手性的,因为有关IrPMe2Ph键的构象。该盐的低温31P 1H} NMR光谱(-75°C,CD3COCD3)显示出主要的ABCD成分(95%)与晶体中的手性构象一致,而次要的AB2C成分(5%)对应于对称的非手性异构体。这些异构体通过绕IrPMe2Ph键旋转而相互转化,并在45°C下获得清晰的聚结AB2C光谱。在低温1H NMR光谱中,主要的手性异构体显示出非等价的原质子,而次要的非手性异构体给出了这些质子的单个共振。对于PMePh2复合物,观察到了相关的旋转异构体,但我们无法获得[IrCl2(PMe3)4] +的冻结光谱。我们得出的结论是,即使对于这