Understanding the Electronic Structure and Stability of B_nX_n^0/2– (n = 4, 6; X = H, F, Cl, Br, I, At, Ts) Clusters^†

Abstract

Main observation and conclusion Borane clusters and their derivatives have attracted extensive attention in inorganic chemistry due to their fascinating multi‐center bonding patterns and physicochemical properties. Here we report a systematic theoretical investigation on the geometry, electronic structure and chemical bonding of BnXn0/2‐ (n = 4, 6; X = H, F, Cl, Br, I, At, Ts) clusters, attempting to explore their bonding features, exceptional stability and the ligand effect. We find that the electronic structure and stability of BnXn0/2‐ clusters can be tuned by the size of the boron cage and electronegativity of the ligand. Fragment orbital energy matching and orbital overlap are of great importance to the covalency of the cluster. In addition to the ionic electrostatic interaction that dominates the bonding interaction and decreases as the ligand becomes heavier, multi‐center bonding covalency determined by the orbital interaction increases accordingly, attributing to the reducing electronegativity. The σ‐donations from the ligand to the boron cage as well as multi‐center two‐electron (nc‐2e) bonding contribute to the σ aromaticity and superb stability. This work reveals the foremost factors that determine the structure and stability of boron clusters, and provides insights into the nature of chemical bonding for species with boron cages and even bulk boron.

Mechanically stable with highly absorptive formamidinium lead halide perovskites [(HC(NH2)2PbX3; X = Br, Cl]: Recent advances and perspectives

“…This parameter provides enlighten on the stability and stiffness of the materials and also show a relationship between the mechanical and dynamic performance of solids. The elastic parameters have examined limited number of earlier researchers for FAPbBr 3 and FAPbCl 3 [36–39]. Particularly, Wang et al [36] have determined the elastic parameters and bulk modulus of formamidinium lead iodide perovskite material and premeditated and are found in good agreement with the present calculations.…”

“…The elastic parameters have examined limited number of earlier researchers for FAPbBr 3 and FAPbCl 3 [36–39]. Particularly, Wang et al [36] have determined the elastic parameters and bulk modulus of formamidinium lead iodide perovskite material and premeditated and are found in good agreement with the present calculations. Guo et al [37] have used first‐principles method for the elastic properties of formamidinium based halide perovskites [FABX 3 ; FA = CH(NH 2 ) 2 ; B = Pb, Sn; X = Br, I] and determined that these materials have a strong anisotropy.…”

Facilely prepared aggregation-induced emission (AIE) nanocrystals with deep-red emission for super-resolution imaging

“…On the other hand, the photo-stable SiR for STED nanoscopy is also included and compared here. 55 It is interesting that although SiR exhibited impressive emission signals with a PLQY of 36.79% in the solution state, an inferior performance with quenched emission was observed in the aggregated thin film (PLQY = 0.14%). However, in the case of DTPA-BT-F, much higher PLQY values in amorphous powders, crystals, and nanocrystals were obtained than that in solution.…”

Advanced developments in nonstoichiometric tungsten oxides for electrochromic applications

“…and tungsten with an empty 5d orbital (conduction band). 126,127 The WO 6 octahedra could be interpreted as a central tungsten metal surrounded by six equidistant oxygen atoms, sharing edges or corners, thus forming a 3D-octahedral crystal structure. 128 In the octahedral geometry, there are hexagonal tunnels and trigonal windows (Figure 3), and the corner sites facilitate the transport of ions.…”