Electronic Effects in Phosphino-Iminophosphorane Pd Complexes upon Varying the N Substituent.

Three series of palladium(II) complexes supported by a phosphine-iminophosphorane ligand built upon an ortho-phenylene core were investigated to study the influence of the iminophosphorane N substituent. Cis-dichloride palladium(II) complexes 1 in which the N atom bears an isopropyl (iPr, 1 a), a phenyl (Ph, 1 b), a trimethylsilyl (TMS, 1 c) group or an H atom (1 d) were synthesized in high yield. They were characterized by NMR, IR spectroscopy, HR-mass spectrometry, elemental analysis, and X-ray diffraction.

Phosphonium Ylides vs Iminophosphoranes: The Role of the Coordinating Ylidic Atom in -[Phosphine-Ylide Rh(CO)] Complexes.

The coordinating properties of two families of ylides, namely, phosphonium ylides and iminophosphoranes, differently substituted at the ylidic center (CH vs NPr), have been investigated in structurally related cationic phosphine-ylide Rh(CO) complexes obtained from readily available phosphine-phosphonium salt precursors derived from an -phenylene bridge. However, while the Rh(CO) complex bearing the P-CH donor moiety proved to be stable, the P═NPr donor end appeared to induce lability to one of the CO groups. All of the Rh carbonyl complexes in both ylide series were fully characterized, including through X-ray diffraction analysis.