CNRS, Laboratoire de Chimie de Coordination, 205, route de Narbonne, F-31077 Toulouse, France.
Magn Reson Chem. 2010 Nov;48(11):848-56. doi: 10.1002/mrc.2677.
(103)Rh NMR represents a powerful tool to assess the global electronic and steric contribution of diphosphine ligands on Rh(COD)(diphosphine) complexes. In the case of DIOP, BINAP and MeDUPHOS, this approach proved to be more informative than classical CO-stretching frequency measurements. After validation, this method has been extended to a set of seven diphosphines. (103)Rh NMR measurements on [Rh(COD)(diphosphine)]PF(6) lead to the following order of donor properties: dppe > MeBPE > MeDUPHOS > dppb > DIOP > BINAP > Tol-BINAP. This trend has been validated by DFT in the case of DIOP, BINAP and MeDUPHOS. In conjunction, (31)P NMR chemical shift has been shown to reflect the ring constraints of the Rh-diphosphine scaffold. This contribution is a step towards a mechanistic investigation of the catalytic hydrogenation of unsaturated substrates by (103)Rh NMR and DFT.
(103)Rh NMR 是一种强大的工具，可用于评估二膦配体对 [Rh(COD)(二膦)]+(+)配合物的整体电子和空间贡献。对于 DIOP、BINAP 和 MeDUPHOS，这种方法比经典的 CO 伸缩频率测量更具信息量。经过验证后，该方法已扩展到一组七种二膦配体。[Rh(COD)(二膦)]PF(6)的 (103)Rh NMR 测量得出以下供电子性质顺序：dppe > MeBPE > MeDUPHOS > dppb > DIOP > BINAP > Tol-BINAP。在 DIOP、BINAP 和 MeDUPHOS 的情况下，通过 DFT 验证了这一趋势。同时，(31)P NMR 化学位移被证明反映了 Rh-二膦骨架的环约束。这一贡献是通过 (103)Rh NMR 和 DFT 对不饱和底物的催化加氢进行机理研究的一步。
