Lorenz Corinna, Hastreiter Florian, Hioe Johnny, Lokesh N, Gärtner Stefanie, Korber Nikolaus, Gschwind Ruth M
Inorganic Chemistry, University of Regensburg, 93040, Regensburg, Germany.
Organic Chemistry, University of Regensburg, 93040, Regensburg, Germany.
Angew Chem Int Ed Engl. 2018 Sep 24;57(39):12956-12960. doi: 10.1002/anie.201807080. Epub 2018 Aug 23.
We report on the first unambiguous detection of the elusive [HSi ] anion in solutions of liquid ammonia by various Si and H NMR experiments including chemical exchange saturation transfer (CEST). The characteristic multiplicity patterns of both the Si and H resonances together with CEST and a partially reduced H, Si coupling constant indicate the presence of a highly dynamic Si entity and a Si-H moiety with slow proton hopping. Theoretical calculations corroborate both reorganization of Si on the picosecond timescale via low vibrational modes and proton hopping. In addition, in a single-crystal X-ray study of (K(DB[18]crown-6))(K([2.2.2]crypt)) [HSi ]⋅8.5 NH , the H atom was unequivocally localized at one vertex of the basal square of the monocapped square-antiprismatic cluster. Thus experimental studies and theoretical considerations provide unprecedented insight into both the structure and the dynamic behavior of these cluster anions, which hitherto had been considered to be rigid.
我们通过包括化学交换饱和转移（CEST）在内的各种硅和氢核磁共振实验，首次明确检测到了液氨溶液中难以捉摸的[HSi]阴离子。硅和氢共振的特征多重峰模式，以及CEST和部分降低的氢-硅耦合常数，表明存在一个高度动态的硅实体和一个质子跳跃缓慢的硅-氢部分。理论计算证实了硅在皮秒时间尺度上通过低振动模式的重组以及质子跳跃。此外，在对（K(DB[18]冠醚-6))(K([2.2.2]穴醚))[HSi]·8.5 NH的单晶X射线研究中，氢原子明确位于单帽方反棱柱簇基底正方形的一个顶点处。因此，实验研究和理论思考为这些簇阴离子的结构和动态行为提供了前所未有的见解，而这些簇阴离子迄今为止一直被认为是刚性的。
