Laboratory of Crystallography, University of Bayreuth, 95440 Bayreuth, Germany.
Phys Rev Lett. 2011 May 27;106(21):215502. doi: 10.1103/PhysRevLett.106.215502. Epub 2011 May 25.
The peculiar bonding situation in γ boron is characterized on the basis of an experimental electron-density distribution which is obtained by multipole refinement against low-temperature single-crystal x-ray diffraction data. A topological analysis of the electron-density distribution reveals one-electron-two-center bonds connecting neighboring icosahedral B(12) clusters. A unique polar-covalent two-electron-three-center bond between a pair of atoms of an icosahedral cluster and one atom of the interstitial B(12) dumbbell explains the observed charge separation in this high-pressure high-temperature polymorph of boron.
γ 硼的特殊成键情况是基于低温单晶 X 射线衍射数据的多极精修实验电子密度分布来描述的。电子密度分布的拓扑分析揭示了连接相邻的二十面体 B(12)团簇的单电子双中心键。在硼的这种高压高温多晶型体中，观察到的电荷分离可以用一对二十面体团簇原子和一个间隙 B(12)哑铃原子之间的独特极性共价双电子三中心键来解释。
