Simple entry into N-tert-butyl-iminophosphonamide rare-earth metal alkyl and chlorido complexes

In situ protolysis reaction of a highly basic and sterically hindered N,f\l'-d tert-butyl-iminophosphonamide ligand Ph2P(=N-tBu)(NH-tBu) = (NPNtBu)H (1) with equimolar or hemimolar amounts of rare-earth metal tris-alkyls leads to dialkyl [(NPNtBu)Ln(CH2SiMe3)(2)(THF)(n)] (Ln = Sc, n = O (2), Ln = Y, n = 1 (3)) and monoalkyl species [(NPNtBu)2Ln(CH2SiMe3)] (Ln = Y (4), Nd (6), Sm (7)). One-pot reaction of [ScCl3(THF)(3)]/1/MeLi in 1/2/3 eq. ratio gives [(NPNOtBu)(2)Sc(THF)CH3] 5. Further reaction of 4 with phenylacetylene resulted in the formation of the Y-alkynyl complex [(NPNtBu)2Y(-CCPh)] 8. Alkyl abstraction in 2, 3 and 4 by reaction with IPhNMe2H+ [B(C6F5)(4)](-) resulted in the formation of cationic alkyl complex ion-pairs [(NPNtBu)Ln(CH2SiMe3)(THF),,J1B(C6F5)411 (Ln - Sc (9), Y (10)) and [(NPN'n)2Y(THF), J1B(C6F5)(4)](-) 11, as confirmed by NMR data. The reaction of bis-NPN alkyl complexes with CHCI3 is the simplest and most reliable protocol to synthesize bis-NPN-chlorido complexes ((NPNtBu)(2)Ln-Cl) (Ln = Sc (12), Y (13), Nd (14), Sm (15), Gd (16), Tb (17), Yb (18) and Lu (19)), which can become new post-metallocene alternatives to the prominent organolanthanide building blocks [Cp*(2)LnX]. Partial hydrolysis of 12 leads to the formation of the oxido/chlorido-capped trinuclear complex [{(NPNtBu)Sc(mu(2)-Cl)}(3)(mu(3)-O)(mu(3)-Cl)] 20. Molecular structures of 4, 6, 7, 13, 19 and 20 were confirmed by X-ray structure analyses.