双(N-杂环卡宾)硼酸钾[BPh 2(t Bu NHC)2 ] K(2')(t Bu NHC = 3-叔丁基咪唑-2-亚基)在甲苯中的意外异构化报道了咪唑基钾–NHC–硼酸钾[BPh 2(t Bu Im)(t Bu NHC)] K(2)(t Bu Im = 3-叔丁基-2-咪唑基)。后者结晶为中心对称二聚体2 2。根据DFT计算的结果,2'的重排基本上是由K +离子的溶剂化触发的:虽然2'在THF溶液中最稳定,但至少在配位甲苯中形成2是可行的,并且通过二聚反应得到2 2极大地有利。后者与GeCl 2 ·二恶烷反应,仅形成前所未见的氯锗次萘基硼酸酯[BPh 2(t Bu Im)(t Bu NHC)] GeCl(3)。治疗3与KHB(小号丁基)3种配料相应hydridogermyliumylideneborate络合物[BPH 2(t Bu Im)( t Bu NHC)] GeH( 4),产率为66%。
New Structural Motifs of Lithium N-Heterocyclic Carbene Complexes with Bis(3-tert-butylimidazol-2-ylidene)dialkylborate Ligands
摘要:
Employment of bidentate, anionic bis(3-tert-butylimidazol-2-ylidene)dialkylborate N-heterocyclic ligands [(BIMBR2)-B-tBu](-) (R = Ph or Me) led to the isolation of two unprecedented lithium carbene complexes: monomeric chelating [((BIMPh2)-Ph-tBu))Li(OEt2)] (4a) and nonchelating, dimeric mu(2)-kappa C-2:kappa C-2'-[((BIMBMe2)-B-tBu)(2)Li-2] 4b). Both have been characterized by spectroscopic methods and by single-crystal X-ray diffraction.