Imidobis(tetraphenylphosphinato)lanthanoid(III) complexes: Synthesis by oxidative protolysis, and redox transmetallation/protolysis, structural studies and Hirshfeld surface analysis

• Redox transmetallation/protolysis (RTP) reactions for synthesis of reactive lanthanoid complexes. • Convenient one pot reactions utilising elemental metals. • Isolation of reaction intermediates to understand reactivity pathway. • Structural studies and Hirshfeld surface analysis of lanthanoid complexes. Redox protolysis of [YbCp 2 (dme)] (dme = 1,2-dimethoxyethane) by imidotetraphenyldiphosphinate, ({Ph 2 PO} 2 NH) LH yields [YbCp{(Ph 2 PO) 2 N} 2 }(MeCN)] 1 and [Yb{(Ph 2 PO) 2 N} 3 ] 2 with the last also obtained by oxidative protolysis of Yb(C 6 F 5 ) 2 . The complexes [Ln{(Ph 2 PO) 2 N} 3 ] ((Ln = Yb 2 , Er 3 , Gd 4 ), [Sm{(Ph 2 PO) 2 N} 3 (MeCN) 3 ] 5 and [Nd{(Ph 2 PO) 2 N} 3 ] 6 have all been prepared by redox transmetallation/protolysis reactions between Yb, Er, Gd, Sm or Nd metals, bispentafluorophenylmercury and proligand LH . Complex 1 is formally eight coordinate with an acetonitrile, cyclopentadienyl (Cp) and two chelating O , O ′-(Ph 2 PO) 2 N ligands, with the MeCN trans to the Cp ring. Complexes 2 and 4· C 7 H 8 are six coordinate monomers with three chelating O , O ′ diphosphinate ligands. By contrast 5 is a highly symmetrical nine-coordinate monomer with three acetonitrile and three chelating O , O ′- L ligands. The three-dimensional Hirshfeld surface (3D-HS) analysis and the two-dimensional fingerprint plots (2D-FP) were quantified for different intermolecular interactions in complexes 2 and 4 .