terdentate ligand systems. Complexes 2 were found to be inactive as catalysts in the atom-transfer radical polymerization (ATRP) reaction of methyl methacrylate (MMA) and in the atom-transfer radical addition (ATRA, Kharasch addition) reaction of CCl4 to MMA. This is ascribed to the relatively high oxidation potential of NiII−Phebox complexes, which excludes the (reversible) formation of a d7-NiIII−Phebox
通过两种合成路线(A和B)合成了2,6-双(
恶唑啉基)苯基
镍溴化物络合物[NiBr(R,R'-Phebox)](2)。在路径A中,选择性双-邻[R,R'-PheboxBr],然后用[NIBR一个转移
金属化反应的
锂化2(PET 3)2 ],得到不仅络合物2与η 3 -聚物- Ñ,Ç,ñ “π-键结合的配位体Phebox而且[NIBR(R,R'-Phebox)(PET 3)2 ],7,其中,所述
镍中心η 1 - ç键合到环内ç本位的Phebox的
配体。两个PEt 3
配体的配位完成7中Ni中心的方平面配位球。当R = t- Bu,R′= H时,仅形成络合物7c。可替代地,当遵循路线B(用[Ni(cod) 2 ]进行氧化加成,cod =
环辛二烯)时,观察到复合物2的选择性形成。得到了[NiBr-( i -Pr,H-Phebox)]( 2b)和[NiBr(双(酮
亚胺)苯基)]( 3)的X射线晶体结构