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As early as 1975, Pitzer suggested that copernicium, flerovium, and oganesson are volatile substances behaving like noble gas because of their closed-shell configurations and accompanying relativistic effects. It is, however, precarious to predict the chemical bonding and physical behavior of a solid by knowledge of its atomic or molecular properties only. Copernicium and oganesson have been analyzed very recently by our group. Both are predicted to be semiconductors and volatile substances with rather low melting and boiling points, which may justify a comparison with the noble gas elements. Here, we study closed-shell flerovium in detail to predict its solid-state properties, including the melting point, by decomposing the total energy into many-body forces derived from relativistic coupled-cluster theory and from density functional theory. The convergence of such a decomposition for flerovium is critically analyzed, and the problem of using density functional theory is highlighted. We predict that flerovium in many ways does not behave like a typical noble gas element despite its closed-shell 7 p 1 / 2 2 configuration and resulting weak interactions. Unlike the case of noble gases, the many-body expansion in terms of the interaction energy does not converge smoothly. This makes the accurate prediction of phase transitions very difficult. Nevertheless, a first prediction by Monte Carlo simulation estimates the melting point at 284 ± 50 K. Furthermore, calculations for the electronic bandgap suggests that flerovium is a semiconductor similar to copernicium. [ABSTRACT FROM AUTHOR]

The reaction between [Li(dme)AsH2] and (ClSiiPr2)2O gives a mixture of two products: the primary diarsanyldisiloxan (H2AsSiiPr2)2O (5) and the cyclic diarsanylsiloxane (HAsSiiPr2)2O (6). Through metallation of the mixture, the deprotonated species of both compounds could be obtained and isolated. Further reactions between the two metallated cyclic diarsanylsiloxanes (compounds 9 and 10) and (ClSiiPr2)2O both lead to the bicyclic compound As2- [(iPr2Si)2O]2 (11). Subsequent oxidative coupling of 9 or 10 with C2H4Br2 as reagent leads to intermolecular As-As bond formation, yielding the quite remarkable compound As6- [(iPr2Si)2O]3 (12), which features two siloxane-bridged As3 rings. Compounds 5-12 were characterized by NMR, elemental analysis and X-ray crystallography. Quantum chemical calculations were carried out to investigate the formation of the different products when arsenic (compound 12) is substituted by phosphorus (compound 4) in the final oxidation reaction of the cyclic compounds (HESiiPr2)2O. The calculations suggest a reaction path leading to 4 that is in agreement with experimental observations. The theoretical data also provide information that explains the experimental finding that two different products for E = P and E = As are formed under the same oxidative reaction conditions. [ABSTRACT FROM AUTHOR]

The triangular clusters [Zn3Cp*3]+ and [Zn2CuCp*3] were obtained by addition of the in situ generated, electrophilic, and isolobal species [ZnCp*]+ and [CuCp*] to Carmona's compound, [Cp*ZnZnCp*], without splitting the ZnZn bond. The choice of non-coordinating fluoroaromatic solvents was crucial. The bonding situations of the all-hydrocarbon-ligand-protected clusters were investigated by quantum chemical calculations revealing a high degree of σ-aromaticity similar to the triatomic hydrogen ion [H3]+. The new species serve as molecular building units of Cu nZn m nanobrass clusters as indicated by LIFDI mass spectrometry. [ABSTRACT FROM AUTHOR]

Quantum chemical calculations using density functional theory have been carried out for the cyclic (alkyl)(amino)carbene (cAAC) complexes of the group 11 atoms [TM(cAAC)2] (TM = Cu, Ag, Au) and their cations [TM(cAAC)2]+. The nature of the metal--ligand bonding was investigated with the charge and energy decomposition analysis EDA-NOCV. The calculations show that the TM--C bonds in the charged adducts [TM(cAAC)2]+ are significantly longer than in the neutral complexes [TM(cAAC)2], but the cations have much higher bond dissociation energies than the neutral molecules. The intrinsic interaction energies ΔEint in [TM(cAAC)2]+ take place between TM+ in the ¹S electronic ground state and (cAAC)2. In contrast, the metal--ligand interactions in [TM(cAAC)2] involve the TM atoms in the excited ¹P state yielding strong TM p(π) → (cAAC)2 π backdonation, which is absent in the cations. The calculations suggest that the cAAC ligands in [TM(cAAC)2] are stronger π acceptors than σ donors. The trends of the intrinsic interaction energies and the bond dissociation energies of the metal--ligand bonds in [TM(cAAC)2] and [TM(cAAC)2]+ give the order Au > Cu > Ag. Calculations at the nonrelativistic level give weaker TM--C bonds, particularly for the gold complexes. The trend for the bond strength in the neutral and charged adducts without relativistic effects becomes Cu > Ag > Au. The EDA-NOCV calculations suggest that the weaker bonds at the nonrelativistic level are mainly due to stronger Pauli repulsion and weaker orbital interactions. The NBO picture of the C--TM--C bonding situation does not correctly represent the nature of the metal-ligand interactions in [TM(cAAC)2]. [ABSTRACT FROM AUTHOR]

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HBCBH and HAlCAlH are related electron-deficient molecules, predicted as local minima on their respective potential energy surfaces. Different views of their electronic structure-as allenes, carbenes, or carbones-prompted two research groups to a friendly competition exploring the predilection of these small molecules to dimerize. Many such dimers emerged from the calculations, some with large enthalpies favoring dimerization. Most interesting among these is an octahedral didehydrocarborane (or alane). The menagerie of (HECEH), E = B, Al structures obtained shows great variety in its bonding patterns. That variety is instructive, for it points to the necessity of examining dimerization for any theoretically postulated metastable molecule. We also learn of the continuing utility of simple Lewis structures, the acid-base reactivity of carbones and carbenes, and the dominant role of electron deficiency in borane and alane chemistry. [ABSTRACT FROM AUTHOR]