Diamidophosphine as a Precursor of the Iminophosphonamidinate Ligand in the Yttrium Complex

Abstract

Diamidophosphine tBuP(NHMes)2(H2L) is synthesized by the treatment of tBuPCl2 with two equivalents of KNHMes (Mes = 2,4,6-Me3C6H2). The reaction of H2L with potassium hydride in THF (THF is tetrahydrofuran) affords the anionic form HL− with the hydrogen atom migrating from nitrogen to phosphorus, which is confirmed by the 1H and 31P NMR data. The structure of the formed iminophosphonamidinate anion HL− is determined by X-ray diffraction (XRD) in the crystalline phase of K[K(THF)2](tBuPH(NMes)2)2 · C7H8 (KHL). The reaction of KHL with yttrium chloride gives complex [Y(tBuPH(NMes)2)2Cl] ([Y(HL)2Cl]) in which, according to the XRD data, ligands HL− are in the iminophosphonamidinate PH form. The 1H and 31P NMR spectra confirm that this structure of the complex exists in the solution.