Photoelectron Spectroscopy of Size-Selected Bismuth–Boron Clusters: BiB_n^– (n = 6–8)

Abstract

Because of its low toxicity, bismuth is considered to be a "green metal" and has received increasing attention in chemistry and materials science. To understand the chemical bonding of bismuth, here we report a joint experimental and theoretical study on a series of bismuth-doped boron clusters, BiB n − (n = 6−8). Well-resolved photoelectron spectra are obtained and are used to understand the structures and bonding of BiB n − in conjunction with theoretical calculations. Global minimum searches find that all three BiB n − clusters have planar structures with the Bi atom bonded to the edge of the planar B n moiety via two Bi−B σ bonds as well as π bonding by the 6p z orbital. BiB 6 − is found to consist of a double-chain B 6 with a terminal Bi atom. Both BiB 7 − and BiB 8 − are composed of a Bi atom bonded to the planar global minima of the B 7 − and B 8 − clusters. Chemical bonding analyses reveal that BiB 6 − is doubly antiaromatic, whereas BiB 7 − and BiB 8 − are doubly aromatic. In the neutral BiB n (n = 6−8) clusters, except BiB 6 which has a planar structure similar to the anion, the global minima of both BiB 7 and BiB 8 are found to be halfsandwich-type structures due to the high stability of the doubly aromatic B 7 3− and B 8 2− molecular wheel ligands.

Structures, and electronic and spectral properties of single-atom transition metal-doped boron clusters MB24− (M = Sc, Ti, V, Cr, Mn, Fe, Co, and Ni)

“…E-mail: leesxoptics@163.com b College of Physics, Guizhou University, Guiyang 550025, Guizhou, People's Republic of China structures, but had been unable to experimentally determine the existence of caged boron clusters. In 2014, the cage-type allboron cluster borospherene B 40 À was experimentally found. 15 Borospherene B 40 À exhibits a hollow cage-like structure, but has different electronic structures and properties from C fullerenes.…”

“…Similar to fullerenes, doped (especially for mono-atom) boron clusters can produce new structures or properties. 18,[20][21][22][28][29][30][31][32][33][34][35][36][37][38][39][40][41] For example, B 20 À , B 22 À , and B 24 have a quasiplanar, quasi-planar, and double-ring tubular structure, 10,42 respectively. However, aer adding alkali metal atoms, both LiB 20 À and MB 22 À (M ¼ Na, K) possess a double-ring tubular structure and Li 2 B 24 possesses a three-ring tubular structure.…”

“…30 Experimental and theoretical studies have found that transition metal atom doped boron clusters ReB n À (n 11) and La 3 B 18 À have various unique structures. [33][34][35][36][37][38][39][40][41] Metal encapsulation is known as an effective approach to modify the chemical bonding and occupancy of energy levels of clusters. Metal (or metal cluster) encapsulation has also been suggested as a possible synthesis pathway for stabilizing the unstable boron fullerene analogue.…”

Structural transformations in boron clusters induced by metal doping

“…84 A similar structure was experimentally confirmed for B 6 Bi − , whose double antiaromaticity favors the planar elongated chain. 85 With Zr, the hexagonal B framework bends in a boat-like conformation engulfing the TM. 66…”

Structural and Electronic Properties of Single-Atom Transition Metal-Doped Boron Clusters MB24 (M = Sc, V, and Mn)

“…Similar to fullerenes, doping of metal atoms into boron clusters can produce new structures or properties. ,− ,− For example, in the case of an alkali metal, experimental research combined with theoretical calculation revealed that B 20 – , B 22 – , and B 24 have a quasi-planar structure, quasi-planar structure, and double-ring tubular structure, , respectively. However, both LiB 20 – and MB 22 – (M = Na and K) possess a double-ring tubular structure and Li 2 B 24 possesses a three-ring tubular structure. ,, In addition, Li-, Na-, or K-doped borospherene B 40 is expected to become a nonlinear optical (NLO) nanomaterial .…”