A stacking interaction between a bridging hydrogen atom and aromatic pi density in the n-B18H22-benzene system.
A stacking interaction between a bridging hydrogen atom and aromatic pi density in the n-B18H22-benzene system.
复制标题
n-B18H22-苯系统中桥联氢原子与芳香族 pi 密度之间的堆积相互作用。
作者：
E. Hamilton;R. Kultyshev;B. Du;E. Meyers;Sheng;C. Hadad;S. Shore
n-B18H22 和 n-B18H22 x C6H6 的结构通过 -60 摄氏度下的单晶 X 射线分析确定。硼簇本身的几何形状似乎并未明显受到溶剂化的影响。然而，聚硼烷桥接氢原子与苯π体系似乎存在不寻常的相互作用，从而产生扩展的堆叠结构。 [D6]苯中 n-B18H22 的 1H{11B} 光谱与 [D12]环己烷中的 1H{11B} 光谱在桥联质子区域的差异最为明显。从脂肪族溶剂转移到芳香族溶剂后，屏蔽增加最大的是与苯的 pi 系统相互作用的桥氢原子对应的信号；信号向上场移动了 0.49 ppm。对 n-B18H22 单元与苯的 1:1 和 2:1 配合物进行了密度泛函理论计算。
The structures of n-B18H22 and of n-B18H22 x C6H6 were determined by single-crystal X-ray analysis at -60 degrees C. The geometry of the boron cluster itself does not seem to be appreciably affected by solvation. There does, however, appear to be an unusual interaction of a polyborane bridging hydrogen atom with the benzene pi system, giving rise to an extended stacked structure. The 1H{11B} spectrum of n-B18H22 in [D6]benzene differs from that in [D12]cyclohexane most noticeably in the bridging proton region. Upon moving from the aliphatic to the aromatic solvent, the greatest increase in shielding was for the signal corresponding to the bridge hydrogen atom that interacts with the pi system of benzene; the signal was shifted upfield by 0.49 ppm. Density functional theory calculations were performed on 1:1 and 2:1 complexes of the n-B18H22 unit with benzene.