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The structure and properties of two‐dimensional phosphoborane sheets were computationally investigated using Density Functional Theory calculations. The calculated phonon spectrum and band structure point to dynamic stability and allowed characterization of the predicted two‐dimensional material as a direct‐gap semiconductor with a band gap of ~1.5 eV. The calculation of the optical properties showed that the two‐dimensional material has a relatively small absorptivity coefficient. The parameters of the mechanical properties characterize the two‐dimensional phosphoborane as a relatively soft material, similar to the monolayer of MoS₂. Assessment of thermal stability by the method of molecular dynamics indicates sufficient stability of the predicted material, which makes it possible to observe it experimentally.

 

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. 

We reply to the comment by S. Pan and G. Frenking who challenged our interpretation of the Na⁻:→BH₃dative bond in the recently synthesized NaBH₃⁻cluster. Our conclusion remains the same as that in our original paper (https://doi.org/10.1002/anie.201907089andhttps://doi.org/10.1002/ange.201907089). This conclusion is additionally supported by the energetic pathways and NBO charges calculated at UCCSD and CASMP2(4,4) levels of theory. We also discussed the suitability of the Laplacian of electron density (QTAIM) and Adaptive Natural Density Partitioning (AdNDP) method for bond type assignment. It seems that AdNDP yields more sensible results. This discussion reveals that the complex realm of bonding is full of semantic inconsistencies, and we invite experimentalists and theoreticians to elaborate this topic and find solutions incorporating different views on the dative bond.

 

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. 

We report a Na:⁻→B dative bond in the NaBH₃⁻cluster, which was designed on the principle of minimum‐energy rupture, prepared by laser vaporization, and characterized by a synergy of anion photoelectron spectroscopy and electronic structure calculations. The global minimum of NaBH₃⁻features a Na−B bond. Its preferred heterolytic dissociation conforms with the IUPAC definition of dative bond. The lone electron pair revealed on Na and the negative Laplacian of electron density at the bond critical point further confirm the dative nature of the Na−B bond. This study represents the first example of a Lewis adduct with an alkalide as the Lewis base.

 

In a high‐resolution photoelectron imaging and theoretical study of the IrB₃⁻cluster, two isomers were observed experimentally with electron affinities (EAs) of 1.3147(8) and 1.937(4) eV. Quantum calculations revealed two nearly degenerate isomers competing for the global minimum, both with a B₃ring coordinated with the Ir atom. The isomer with the higher EA consists of a B₃ring with a bridge‐bonded Ir atom (C_s,²A′), and the second isomer features a tetrahedral structure (C_3v,²A₁). The neutral tetrahedral structure was predicted to be considerably more stable than all other isomers. Chemical bonding analysis showed that the neutralC_3visomer involves significant covalent Ir−B bonding and weak ionic bonding with charge transfer from B₃to Ir, and can be viewed as an Ir–(η³‐B₃⁺) complex. This study provides the first example of a boron‐to‐metal charge‐transfer complex and evidence of a π‐aromatic B₃⁺ring coordinated to a transition metal.

 

The Al=Al double bond is elusive in chemistry. Herein we report the results obtained via combined photoelectron spectroscopy and ab initio studies of the LiAl₂H₄⁻cluster that confirm the formation of a conventional Al=Al double bond. Comprehensive searches for the most stable structures of the LiAl₂H₄⁻cluster have shown that the global minimum isomer I possesses a geometric structure which resembles that of Si₂H₄, demonstrating a successful example of the transmutation of Al atoms into Si atoms by electron donation. Theoretical simulations of the photoelectron spectrum discovered the coexistence of two isomers in the ion beam, including the one with the Al=Al double bond.

 

Following an ongoing interest in the study of transition metal complexes with exotic bonding networks, we report herein the synthesis of a family of heterobimetallic triangular clusters involving Ru and Pd atoms. These are the first examples of trinuclear complexes combining these nuclei. Structural and bonding analyses revealed both analogies and unexpected differences for these [Pd 2 Ru] + complexes compared to their parent [Pd 3 ] + peers. Noticeably, participation of the Ru atom in the π-aromaticity of the coordinated benzene ring makes the synthesized compound the second reported example of ‘bottled’ double aromaticity. This can also be referred to as spiroaromaticity due to the participation of Ru in two aromatic systems at a time. Moreover, the [Pd 2 Ru] + kernel exhibits unprecedented orbital overlap of Ru d z2 AO and two Pd d xy or d x2−y2 AOs. The present findings reveal the possibility of synthesizing stable clusters with delocalized metal–metal bonding from the combination of non-adjacent elements of the periodic table which has not been reported previously.