Transition-metal-like bonding behaviors of a boron atom in a boron-cluster boronyl complex [(η⁷-B₇)-B-BO]⁻

Abstract

Boron displays many unusual structural and bonding properties due to its electron deficiency. Here we show that a boron atom in a boron monoxide cluster (B9O−) exhibits transition-metal-like properties. Temperature-dependent...

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

“…Numerous metal-doped boron clusters have also been produced and studied, significantly expanding the structural diversity of nanoborons. The study on transition-metal-doped boron clusters revealed the existence of various structures including metal-centered borometallic molecular wheels, − metallo-boronanotubes, and metallo-borophenes. , The PrB 7 – cluster contains a half-sandwich structure featuring a B 7 3– moiety, which was also found recently in B 9 O – . Dilanthanide boron clusters were found to form inverse sandwiches, , while La 3 B 18 – features the first spherical trihedral metallo-borospherene …”

“…The global minimum of B 7 – is a triplet with two unpaired electrons and a C 6 v structure . The closed-shell B 7 3– species is known to be doubly aromatic and forms half-sandwich type clusters, first observed in PrB 7 and recently in B 7 –B–BO – . , It has been used to design several binary clusters computationally. − Thus, the stability of the C 6 v BiB 7 is a consequence of the high stability of the doubly aromatic B 7 3– species; the three 6p electrons participate in the π bonding with the B 7 moiety to fulfill the π aromaticity. Thus, the C 6 v BiB 7 can be viewed as [η 7 -B 7 3– ]­[Bi 3+ ], where the metallic bonding property of Bi is manifested.…”

“…3− species is known to be doubly aromatic and forms half-sandwich type clusters, first observed in PrB 7 and recently in B 7 −B−BO − . 22,23 It has been used to design several binary clusters computationally. 66−68 Thus, the stability of the C 6v BiB 7 is a consequence of the high stability of the doubly aromatic B 7 3− species; the three 6p electrons participate in the π bonding with the B 7 moiety to fulfill the π aromaticity.…”

“…− cluster contains a half-sandwich structure featuring a B 7 3− moiety, 22 which was also found recently in B 9 O − . 23 Dilanthanide boron clusters were found to form inverse sandwiches, 24,25 while La 3 B 18 − features the first spherical trihedral metallo-borospherene. 26 Bismuth is the heaviest stable metal element in the periodic table, but it has low toxicity relative to its neighbors.…”

Structural transformations in boron clusters induced by metal doping

“…This is illustrated in more detail in B 7 Pr, where the delocalized σ- and π-bonds give rise to the double aromaticity of B 7 3− , which is the driving force in shaping these concave structures since the B 6 ring is too small to incorporate the central B atom in B 7 3− . 103 In other words, the plunged central B atom shares its valence electrons with the B ring to fulfill double aromaticity, as very recently demonstrated by Tian et al 239 There are umbrella-type structures with several heavy atoms as well as Li and Al in the former case, and with Zr, Nb, Mo, Tc, and Sc in the latter. The B wheels arise either with a dimer along the symmetry axis or with the dopant atom at the center of the wheel as in B 8 Co − and B 9 Ru − , the first experimentally characterized B wheels.…”