The nature of structure and bonding between transition metal and mixed Si‐Ge tetramers: A 20‐electron superatom system

Abstract

A novel superatom species with 20-electron system, Six Gey M(+) (x + y = 4; M = Nb, Ta), was properly proposed. The trigonal bipyramid structures for the studied systems were identified as the putative global minimum by means of the density functional theory calculations. The high chemical stability can be explained by the strong p-d hybridization between transition metal and mixed Si-Ge tetramers, and closed-shell valence electron configuration [1S(2) 1P(6) 2S(2) 1D(10) ]. Meanwhile, the chemical bondings between metal atom and the tetramers can be recognized by three localized two-center two-electron (2c-2e) and delocalized 3c-2e σ-bonds. For all the doped structures studied here, it was found that the π- and σ-electrons satisfy the 2(N + 1)(2) counting rule, and thus these clusters possess spherically double (π and σ) aromaticity, which is also confirmed by the negative nucleus-independent chemical shifts values. Consequently, all the calculated results provide a further understanding for structural stabilities and electronic properties of transition metal-doped semiconductor clusters. © 2016 Wiley Periodicals, Inc.

Structural evolution and bonding properties of BSin−/ (n = 4–12) clusters: Size-selected anion photoelectron spectroscopy and theoretical calculations

“…The HOMOs are all doubly occupied, and the LUMO is higher in energy than the HOMO by 3.27 eV, although the previous investigations have revealed that the HOMO-LUMO gap calculated with the B3LYP functional is more overestimate than that obtained from the other functional (BP86) by ∼1.00 eV. [67][68][69] This indicates that the BSi 11 − anion has a shell-closed electronic structure with a large HOMO-LUMO gap. The HOMO is a Si-Si σ orbital with bonding characters, mainly composed by the 3p orbitals of Si atoms.…”

The chemical bonding and spectral assignments of rhodium(III)-catalyzedcloso-dodecaborate complexes: Ab initio study

“…At the hybrid B3LYP level, the E g value of the complex is predicted to be 2.90 eV, which is calculated from the HOMO (−6.02 eV) and the LUMO (−3.12 eV). A large E g value is strongly related with high‐kinetic stability . This is because that the compounds with the large gaps are energetically unfavorable to add electrons to a high‐lying LUMO or to extract electrons from a low‐lying HOMO, and to form the activated compounds of any potential reaction.…”

“…We performed the AdNDP analysis for the RhCD complex, to further elucidate the nature of chemical bonding. As previously reported, this AdNDP method is very efficient to gain insight into the bonding features and has been successfully utilized for the fullerene derivatives, boron, and transition‐metal doped semiconductor clusters . Meanwhile, the AdNDP method is proposed on the basis of the electron pairs in such compounds, and represents the chemical bondings in terms of the forms of n ‐center two‐electron ( n c‐2e) bonds, where n goes from one (lone‐pairs) to maximum number of atoms, defined as 1c‐2e (lone‐pairs), 2c‐2e, 3c‐2e, and so forth.…”

“…Geometry optimizations of the RhCD complexes were performed by DFT with the hybrid B3LYP functional in conjunction with Karlsruhe split‐valence def‐SVP basis set augmented with polarization functions for all the atoms, as implemented in the Gaussian 09 programs . The method provides a better energy prediction for evaluating the structural stability of complexes . In the computation, the singlet and triplet spin states (spin multiplicities 2 S + 1 = 1, 3) were considered for initial structure.…”

First-Principles Study of Structural, Electronic and Magnetic Properties of Metal-Centered Tetrahexahedral V15+ Cluster

“…In order to gain insight into the chemical bonding of the V 15 + cluster, the n -center two-electron ( n c-2e, n going from one (lone-pair) to the maximum number of clusters) bonds were, for the first time, explored using the adaptive natural density partitioning (AdNDP) method proposed by Zubarev and Boldyrev [ 44 ], which has been successfully used to reveal bonding characteristics not only for organic aromatic molecules [ 48 , 49 ], but also for boron [ 50 , 51 ] and transition-metal doping clusters [ 52 , 53 , 54 ].…”