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Abstract Sandwich-type clusters with the planar fragment containing a heterometallic sheet have remained elusive. In this work, we introduce the [K(2,2,2-crypt)] 4 {(Ge 9 ) 2 [ η 6 -Ge(PdPPh 3 ) 3 ]} complex that contains a heterometallic sandwich fragment. The title compound is structurally characterized by means of single-crystal X-ray diffraction, which reveals the presence of an unusual heteroatomic metal planar fragment Ge@Pd 3 . The planar fragment contains a rare formal zerovalent germanium core and a peculiar bonding mode of sp 2 -Ge@(PdPPh 3 ) 3 trigonal planar structure, whereas the nonagermanide fragments act as capping ligands. The chemical bonding pattern of the planar fragment consists of three 2c-2e Pd-Ge σ-bonds attaching Pd atoms to the core Ge atom, while the binding between the planar fragment and the aromatic Ge 9 ligands is provided by six 2c-2e Pd-Ge σ-bonds and two delocalized 4c-2e σ-bonds. The synthesized cluster represents a rare example of a sandwich compound with the heteroatomic metal planar fragment and inorganic aromatic capping ligands. 

In this work, we report a dimeric cluster anion, {[CuGe 9 Mes] 2 } 4− , which was isolated as the [K(2,2,2-crypt)] + salt and characterized by using single-crystal X-ray diffraction and ESI mass spectroscopy. The title cluster represents the first locally σ-antiaromatic compound in the solid state, as well as the first heteroatomic antiaromatic compound. 

Nonagermanide clusters are widely used in inorganic synthesis and are actively studied by experimentalists and theoreticians. However, chemical bonding of such versatile species is still not completely understood. In our work we deciphered a bonding pattern for various experimentally obtained nonagermanide species. We localized the electron density via the AdNDP algorithm for the model structures ([Ge 9 ] 4− , [Ge 9 {P(NH 2 ) 2 } 3 ] − , Cu[Ge 9 {P(NH 2 ) 2 } 3 ] and Cu(NHC)[Ge 9 {P(NH 2 ) 2 } 3 ]) and obtained a simple and chemically intuitive bonding pattern which can explain the variety of active sites and the existence of both D 3h and C 4v geometries for such clusters. Moreover, the [Ge 9 ] 4− core is found to be a unique example of an inorganic Zintl cluster with multiple local σ-aromaticity. 

A novel approach to chemical bond analysis for excited states has been developed. Using an extended adaptive natural density partitioning method (AdNDP) as implemented in AdNDP 2.0 code, we obtained chemically intuitive bonding patterns for the excited states of H 2 O, B 5 + , and C 2 H 4 + molecules. The deformation pathway in the excited states could be easily predicted based on the analysis of the chemical bond pattern. We expect that this new method of chemical bonding analysis would be very helpful for photochemistry, photoelectron spectroscopy, electron spectroscopy and other chemical applications that involved excited states. 

Among the diversity of new materials, two-dimensional crystal structures have been attracting significant attention from the broad scientific community due to their promising applications in nanoscience. In this study we predict a novel two-dimensional ferromagnetic boron material, which has been exhaustively studied with DFT methods. The relaxed structure of the 2D-B 6 monolayer consists of slightly flattened octahedral units connected with 2c-2e B–B σ-bonds. The calculated phonon spectrum and ab initio molecular dynamics simulations reveal the thermal and dynamical stability of the designed material. The calculation of the mechanical properties indicate a relatively high Young's modulus of 149 N m −1 . Moreover, the electronic structure indicates the metallic nature of the 2D-B 6 sheets, whereas the magnetic moment per unit cell is found to be 1.59 μ B . The magnetism in the 2D-B 6 monolayer can be described by the presence of two unpaired delocalized bonding elements inside every distorted octahedron. Interestingly, the nature of the magnetism does not lie in the presence of half-occupied atomic orbitals, as was shown for previously studied magnetic materials based on boron. We hope that our predictions will provide promising new ideas for the further fabrication of boron-based two-dimensional magnetic materials.