Yttrium and scandium complexes of a bulky bis(phosphinimine)carbazole ligand

The synthesis and reactivity of a bulky bis(phosphinimine) carbazole pincer ligand (HL) bearing mesityl N-aryl groups is described. Reaction of HL with Y(CH2SiMe3)(3)(THF)(2) afforded a doubly cyclometalated organoyttrium complex, whereby the ligand was k(3)N, k(2)C coordinated to the metal via three nitrogen atoms and two ortho-metalated P-phenyl rings. Deprotonation of (HL) with (BuLi)-Bu-n liberated a monomeric and thermally stable lithium salt of the ligand (LLi). Salt metathesis reactions of LLi with ScCl3(THF)(3) and YCl3(THF)(3.5) generated the corresponding rare earth dichloro complexes, which were found to be monomeric and Lewis-base free. (C) 2014 Elsevier B. V. All rights reserved.