Interpenetration of a 3D Icosahedral M@Ni12 (M=Al, Ga) Framework with Porphyrin-Reminiscent Boron Layers in MNi9 B8.
Interpenetration of a 3D Icosahedral M@Ni12 (M=Al, Ga) Framework with Porphyrin-Reminiscent Boron Layers in MNi9 B8.
复制标题
3D 二十面体 M@Ni12 (M=Al, Ga) 框架与 MNi9 B8 中卟啉记忆硼层的互穿。
作者：
Q. Zheng;F. Wagner;A. Ormeci;Y. Prots;U. Burkhardt;M. Schmidt;W. Schnelle;Y. Grin;A. Leithe
采用混合元素热处理的方法合成了两种三元硼化物MNi_9 B_8（M=Al，Ga）。单晶X射线衍射数据表明，AlNi 9 B8和GaNi 9 B8晶体具有新型结构，空间群为Cmcm，晶格常数分别为a=7.0896（3），B=8.1181（3），c=10.6497（4）和a=7.0897（5），B=8.1579（4），c=10.6648（7）。 硼原子构建了二维层，其由具有两个拖尾B原子的褶皱[B16 ]环组成，而M原子驻留在扭曲的垂直凝聚[Ni 12]二十面体中，其形成由硼卟啉类层相互渗透的三维框架。[B16 ]环形成了一个不寻常的局部排列，类似于一个巨大的金属卟啉实体，由于它们的环尺寸约为8 μ m，螯合了12个二十面体Ni原子中的4个。 通过电子局域化方法的化学键的分析表明，强的共价B-B相互作用和弱的Ni-Ni相互作用。Al-Ni骨架与硼层之间存在多中心配价B-Ni相互作用。与化学键分析和能带结构计算一致，AlNi 9 B8是一种保利顺磁金属。
Two ternary borides MNi9 B8 (M=Al, Ga) were synthesized by thermal treatment of mixtures of the elements. Single-crystal X-ray diffraction data reveal AlNi9 B8 and GaNi9 B8 crystallizing in a new type of structure within the space group Cmcm and the lattice parameters a=7.0896(3) Å, b=8.1181(3) Å, c=10.6497(4) Å and a=7.0897(5) Å, b=8.1579(4) Å, c=10.6648(7) Å, respectively. The boron atoms build up two-dimensional layers, which consist of puckered [B16 ] rings with two tailing B atoms, whereas the M atoms reside in distorted vertices-condensed [Ni12 ] icosahedra, which form a three-dimensional framework interpenetrated by boron porphyrin-reminiscent layers. An unusual local arrangement resembling a giant metallo-porphyrin entity is formed by the [B16 ] rings, which, due to their large annular size of approximately 8 Å, chelate four of the twelve icosahedral Ni atoms. An analysis of the chemical bonding by means of the electron localizability approach reveals strong covalent B-B interactions and weak Ni-Ni interactions. Multi-center dative B-Ni interaction occurs between the Al-Ni framework and the boron layers. In agreement with the chemical bonding analysis and band structure calculations, AlNi9 B8 is a Pauli-paramagnetic metal.
影响因子：
19
作者：
Kunstmann, Jens;Bezugly, Viktor;Cuniberti, Gianaurelio
通讯作者：
Cuniberti, Gianaurelio