Spontaneous HCl elimination in group 10 metal complexes with a multidonor phosphinoamide ligand.

• A multidonor amidophosphine ligand was prepared using an alternative route. • The ligand reacts with group 10 metal dichloride precursors to produce P,N,N-chelate complexes. • Spontaneous HCl elimination occurs during the complexation. • Terminal chloride ligand can be replaced for a phosphine. • The complexes were fully characterized and possess similar molecular structures. The multidonor amidophosphine 2-Ph 2 PC 6 H 4 NHC(O)C 5 H 4 N, where C 5 H 4 N is a 2-pyridyl substituent, reacted with the synthetic equivalents of group 10 metal dichlorides, viz. [NiCl 2 (dme)], [PdCl 2 (MeCN) 2 ] or [PtCl 2 (cod)] (dme = 1,2-dimethoxyethane, cod = cycloocta-1,5-diene), to produce neutral bis-chelate complexes [MCl(Ph 2 PC 6 H 4 NC(O)C 5 H 4 N-κ3 P,N,N ′)] (M = Ni, Pd, and Pt). During the complexation reaction, spontaneous HCl elimination occurred, possibly as the result of overall structural stabilization by the deprotonation of the amide nitrogen, which is brought toward the metal centers by initial P,N(pyridine)-coordination of the amidophosphine ligand. Subsequent reaction of 3 as the representative with AgClO 4 and triphenylphosphine produced the cationic bis(phosphine) complex [Pd(PPh 3)(Ph 2 PC 6 H 4 NC(O)C 5 H 4 N-κ3 P,N,N ′)]ClO 4 (5), which converted back to parent chloride complex in the presence of chloride ions. All complexes were fully characterized using NMR and IR spectroscopy, mass spectrometry, and elemental analysis. X-ray diffraction analysis for 2, 3, 4 ·½ CH 2 Cl 2 and 5 ·Me 2 CO revealed that compounds 2 – 4 exhibit similar coordination geometry, which is rather marginally affected upon replacement of the chloride for a bulkier phosphine ligand. [Display omitted] [ABSTRACT FROM AUTHOR]