title: Transition metal-boron complexes BnM: from bowls (n = 8-14) to tires (n = 14).
abstract: Transition metal-boron complexes BnM have been predicted at density functional theory level to be molecular bowls (n = 8-14) hosting a transition metal atom (M) inside or molecular tires (n = 14) centered with a transition metal atom. Small Bn clusters prove to be effective inorganic ligands to all the VB-VIIIB transition metal elements in the periodic table. Density functional evidences obtained in this work strongly suggest that bowl-shaped fullerene analogues of Bn units exist in small BnM complexes and the bowl-to-tire structural transition occur to the first-row transition metal complexes BnM (M = Mn, Fe, Co) at n = 14, a size obviously smaller than n = 20 where the 2D-3D structural transition occurs to bare Bn. The half-sandwich-type B12Cr (C3v), full sandwich-type (B12)2Cr (D3d), bowl-shaped B14Fe (C2), and tire-shaped B14Fe (D7d) and B14Fe- (C7v) are the most interesting prototypes to be targeted in future experiments. These BnM complexes may serve as building blocks to form extended boron-rich BnMm tubes or cages (m > or = 2) or as structural units to be placed inside carbon nanotubes with suitable diameters.
authors.affiliation: Institute of Molecular Science, Shanxi University, Taiyuan 030006, Shanxi, People's Republic of China. lisidian@yahoo.com
authors.forename: Si-Dian
authors.initials: SD
authors.lastname: Li
authors.forename: Chang-Qing
authors.initials: CQ
authors.lastname: Miao
authors.forename: Jin-Chang
authors.initials: JC
authors.lastname: Guo
authors.forename: Guang-Ming
authors.initials: GM
authors.lastname: Ren