New Pyridine Dicarbene Ligands with Ring Expanded NHCs and their Nickel and Chromium Complexes
作者:Evangelos Papangelis、Katrin Pelzer、Christophe Gourlaouen、Dominique Armspach、Pierre Braunstein、Andreas A. Danopoulos、Corinne Bailly、Nikolaos Tsoureas、Dimitrios Triantafyllos Gerokonstantis
DOI:10.1002/asia.202400169
日期:——
The pincer complexes [NiIIBr(CNC)]Br (4), [CrIIIBr3(CNC)] (5 a) and [CrIIIBr2.3Cl0.7(CNC)] (5 b), where CNC=3,3′-(pyridine-2,6-diyl)bis(1-mesityl-3,4,5,6-tetrahydropyrimidin-2-ylidene), were obtained from the novel ligand CNC, generated in situ from the precursor (CHNCH)Br2 and [NiIIBr2(PPh3)2] or from [CrIIN(SiMe3)2}2(THF)2] and (CHNCH)Br2 by aminolysis, respectively. The tetrahedrally distorted
钳配合物 [Ni II Br( CNC )]Br ( 4 )、[Cr III Br 3 ( CNC )] ( 5 a ) 和 [Cr III Br 2.3 Cl 0.7 ( CNC )] ( 5 b ),其中CNC =3 ,3'-(吡啶-2,6-二基)双(1-基-3,4,5,6-四氢嘧啶-2-亚基),由新型配体CNC获得,由前体(CHNCH )Br 2和[Ni II Br 2 (PPh 3 ) 2 ]或分别通过氨解得到[Cr II N(SiMe 3 ) 2 } 2 (THF) 2 ]和(CHNCH)Br 2 。四面体扭曲的方形平面( τ 4 ≅0.30)几何形状和Ni 4中的单线态基态归因于CNC主干的空间约束。计算方法强调了配位几何形状和单线态-三线态能量差对四氢嘧啶翼尖N-取代基大小的依赖性,并将其与5元咪唑啉-2-亚基钳类似物的情况进行了对比。 5a和5b中的八面体Cr III金属中心可能是在CH