Structure and Chemical Bonding in Medium-Size Boron Clusters Doped with Praseodymium

Abstract

After reports of unusually low oxidation states of lanthanide elements in Ln−B clusters and their inverse sandwich geometrical topologies, the interest shifted from boride clusters doped with transition metal (TM) elements to the boride clusters doped with lanthanide atoms. In this work, the results obtained by a combined approach consisting of CALYPSO structure predictions and density functional theory (DFT) calculations for the neutral and anionic PrB n series, n = 7−16, are reported. A close agreement between our calculated vertical detachment energies and experimental data supports the accuracy of the results obtained. Contrary to the medium-size TM-doped medium boron clusters, which prefer three types of structural configurations, all lowest-energy states of the medium-size Pr-doped boron clusters have half-sandwich geometries. An interesting structural evolution pattern was found for both neutral and anionic PrB n clusters at n = 7, 10, 13, and 16, which includes quasi-planar B 7 units half-sandwiching the Pr atom. Unusual oxidation numbers of +2 and +1 were found for the Pr atom in the PrB 7 − and PrB 8 − anions, respectively. Chemical bonding analysis for the neutral PrB 7 and PrB 13 clusters revealed that their high stability stems from interactions between Pr 5d and B 2p orbitals. A stable tubular-shaped PrB 30 cluster is proposed as a promising building block for boron-based nanotubes.

Functionalized nona-silicide [Si9R3] Zintl clusters: a new class of superhalogens

“…To overcome the limitation of the Laplacian (r 2 r) and energy density (H) rules in describing the nature of bonding, we further carry out the adaptive natural density partitioning (AdNDP) [53][54][55][56][57][58] analysis using the Multiwfn program. 50 Based on the NBO (Natural Bonding Orbital) theory, AdNDP is a newly developed computational algorithm, which can entirely explain the bonding nature of the molecules, i.e., N-centre-2 electron bond [Nc-2e bond] (where N = number of centers).…”

Designing a Four-Ring Tubular Boron Motif through Metal Doping

“…27−29 clusters. 32 Hence, the question remains as to whether higherring tubular boron clusters exist! During the revision of this paper, Li et al 33 reported that MB 24 − (M = Mn, Fe, Co) clusters have a distorted four-ring tubular structure.…”

“…While some tubular boron or metal-doped boron clusters have been obtained as discussed above, most of them are two-ring tubular cases, and their higher-ring analogues are very scarce. − A few three-ring tubular examples can be found in B 27 + , B 42 , Li 2 B 24 , ScB 24 , and PrB n ( n = 28, 30, 36) clusters . Hence, the question remains as to whether higher-ring tubular boron clusters exist!…”

Structural Evolution and Electronic Properties of Two Sulfur Atom-Doped Boron Clusters

“…In recent years, researchers have mainly focused on the structure and properties of boron clusters doped with metal atoms. ,− ,− For example, single alkali metal atom doping can adjust the quasi-planar pure boron clusters (B 20 – and B 22 – ) to double-ring tubular doped boron clusters (LiB 20 – , NaB 22 – and KB 22 – ). ,,, Single transition metal atom doping can adjust quasi-planar B 12 0/– to semisandwich structure CoB 12 , RhB 12 and TaB 12 – , ,, ,, adjust double-ring tubular B 24 to cage-doped boron clusters (TiB 24 ) and three-ring tubular doped boron clusters (ScB 24 ), ,, adjust quasi-planar B 24 – to cage-doped boron clusters (TiB 24 – and VB 24 – ). , In addition, doped borospherenes MB 40 (M = Li, Na, or K) are expected to be applied in nonlinear optical materials, doped borospherenes CoB 40 and MB 40 (M = Sc, Ti) are expected to be applied in molecular devices and hydrogen storage materials, ,,, and Co- and Rh-doped boron clusters MB 12 – (M = Co, Rh) can improve chemical activity . Single metal atom-doped boron clusters BiB n – ( n = 6–8), MnB n – ( n = 6, 16), and ReB n – ( n = 3–4, 6, 8–9), CoB 16 – and two or three metal atom-doped boron clusters (M 2 B 6 (M = Mg, Ca, Sr), La 2 B 10 – , La 2 B 11 – , La 3 B 18 – , and Sc 3 B 20 ) have various unique structures. − ,, Single Pr atom-doped PrB 4 – can adjust the Pr atom to a very low oxidation state (OS) and single Pr atom-doped PrB n ( n = 7–16) have various unique structures; two metal atom-doped boron clusters Be 2 B 24 + have a four-ring tubular structure . However, nonmetallic atom-doped boron clusters have been less studied, − such as sin...…”