Accessing relatively electron poor cerium(<scp>iv</scp>) hydrazido complexes by lithium cation promoted ligand reduction
作者:Jessica R. Levin、Thibault Cheisson、Patrick J. Carroll、Eric J. Schelter
DOI:10.1039/c6dt03154d
日期:——
Ce(IV) product depended on the substituents on the N,N′-diarylhydrazido ligands. Isolable cerium products formed only with electron withdrawing substituents on the N,N′-diarylhydrazido rings, whereas electron donating substituents resulted in intractable mixtures of Ce(III) products and N,N′-bis(aryl)diazenes (ArNNAr). The presence of electron withdrawing substituents at the N,N′-diarylhydrazido ligands
一系列取代的N,N′-二芳基肼(ArNHNHAr),Ar = 3,5-(CH 3)-C 6 H 3; n =1。-Ph; 4-氯-C 6 H 4;3,5-Cl-C 6 H 3;3,5-(CF 3)-C 6 H 3与Ce(III)[N(SiMe 3)2 ] 3和锂化碱反应,探索使用Ce(III)作为还原剂并评估其影响配合物在所得配合物的铈金属中心电子结构上的取代度。该ñ,在所有情况下,N′-二芳基肼基配体均通过Li +阳离子配位,然后通过Ce(III)阳离子还原以形成Li 4(Et 2 O)4 [Ce IV(ArNNAr)4 ]配合物。所得Ce(IV)产物的稳定性取决于N,N′-二芳基肼基配体上的取代基。可分离的铈产物仅在N,N'-二芳基肼基环上具有吸电子取代基形成,而给电子取代基导致Ce(III)产物和N的难以混合的混合物,N′-双(芳基)二氮烯(ArN NAr)。在N,N'-二芳基肼基配