Revisiting ultra-weak metal-metal bonding

Rohman, Shahnaz S.; Kashyap, Chayanika; Ullah, Sabnam S.; Mazumder, Lakhya J.; Sahu, Prem Prakash; Kalita, Amlanjyoti; Reza, Sohel; Hazarika, P.; Borah, Bichitra; Guha, Ankur K.

doi:10.1016/j.cplett.2019.06.023

Cited by 13 publications

(8 citation statements)

References 28 publications

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“…We note that Liu et al have interpreted the bonding in the octahedral Be 2 (μ 2 ‐Li) 4 cluster, and others, in terms of a Be=Be double‐π bond and the bonding in Be 2 X 4 Y 2 clusters (X = Li, Na and Y = Li, Na, K) in terms of Be≡Be triple bonds . Calculations and analysis carried out by Rohman et al also support the notion of Be≡Be triple bonds in various systems, including Be 2 X 6 (X = Li, Na), but they found the BeBe bonding to be ultraweak in spite of the very short BeBe distances . Indeed, some systems have been studied both experimentally and computationally, such as the rhombic Be 2 O 2 cluster, which feature very short BeBe distances in the absence of any direct BeBe chemical bonding …”

Section: Introductionsupporting

confidence: 54%

“…In spite of the obvious deterrence for experimentalists of the high toxicity of beryllium compounds, a great deal is now known about the organometallic and coordination chemistry of beryllium . Beryllium compounds that have been studied experimentally and especially computationally include various systems that feature BeBe bonding and/or very short BeBe distances . For example, it has been shown for various choices of X, such as a fluorine atom or an appropriate N‐heterocyclic carbene ligand, that certain XBeBeX species feature Be−Be bonds that are both significantly stronger and shorter than the weak and rather long bond in Be 2 .…”

Section: Introductionmentioning

confidence: 99%

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Nature of the chemical bonding inD_3h[MH₃M]⁺cations (M = Be, Mg)

Penotti¹,

Karadakov

Ponec

2020

Int J of Quantum Chemistry

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Motivated by the particularly short metal-metal distance that has been predicted for the D 3h [BeH 3 Be] + cation, comparable to those anticipated for triple bonds, we investigate the nature of the bonding interactions in the D 3h [MH 3 M] + cations (M = Be, Mg). CCSD(T)/cc-pVQZ calculations are used to determine optimized geometries for all of the various species, including those "capped" by He or Ne atoms (as proxies for an inert gas matrix). The primary tools that are then used to investigate the nature of the chemical bonding are spin-coupled generalized valence bond calculations and the analysis of localized natural orbitals and of domain-averaged Fermi holes. The various results for all of the systems considered indicate the presence of highly polar threecenter two-electron M─H─M bonding character instead of any significant direct metal-metal bonding. K E Y W O R D S domain-averaged Fermi hole analysis, localized natural orbitals, spin-coupled generalized valence bond (SCGVB) calculations, three-center two-electron bonding, ultrashort metalmetal distances

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Section: Introductionsupporting

confidence: 54%

Section: Introductionmentioning

confidence: 99%

Nature of the chemical bonding inD_3h[MH₃M]⁺cations (M = Be, Mg)

Penotti¹,

Karadakov

Ponec

2020

Int J of Quantum Chemistry

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“…Many complexes have now been studied experimentally and computationally that feature strong BeBe bonding and/or particularly short BeBe distances, with some authors suggesting unusual and surprising bonding patterns. It has been claimed, for example, that the bonding motif in various Be 2 X 4 Y 2 clusters, in which (X,Y) are alkali metal atoms, involves BeBe triple bonds − whereas that in the octahedral Be 2 (μ 2 -Li) 4 cluster features a BeBe double π bond with no associated σ component . A related example in the ongoing computational pursuit of potentially stable beryllium complexes that feature ultrashort BeBe distances arises from a suggestion that bridging H atoms can simulate the effect of a BeBe triple bond .…”

Section: Insights Into the Electronic Structure Of Moleculesmentioning

confidence: 99%

Spin-Coupled Generalized Valence Bond Theory: New Perspectives on the Electronic Structure of Molecules and Chemical Bonds

Dunning

Cooper

et al. 2021

J. Phys. Chem. A

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Spin-Coupled Generalized Valence Bond (SCGVB) theory provides the foundation for a comprehensive theory of the electronic structure of molecules. SCGVB theory offers a compelling orbital description of the electronic structure of molecules as well as an efficient and effective zero-order wave function for calculations striving for quantitative predictions of molecular structures, energetics and other properties. The orbitals in the SCGVB wave function are usually semi-localized and, for most molecules, can be interpreted using concepts familiar to all chemists (hybrid orbitals, localized bond pair, lone pairs, etc.). SCGVB theory also provides new perspectives on the nature of the bonds in molecules such as C2, Be2 and SF4/SF6. SCGVB theory contributes unparalleled insights into the underlying cause of the first-row anomaly in inorganic chemistry as well as the electronic structure of organic molecules and the electronic mechanisms of organic reactions. The SCGVB wave function accounts for nondynamical correlation effects and, thus, corrects the most serious deficiency in molecular orbital (RHF) wave functions. Dynamical correlation effects, which are critical for quantitative predictions, can be taken into account using the SCGVB wave function as the zero-order wave function for multireference configuration interaction or coupled cluster calculations.* In prior articles in the literature the Spin-Coupled Generalized Valence Bond wave function has usually been referred to as the Spin-Coupled Valence Bond (SCVB) wave function or the full Generalized Valence Bond (full GVB) wave function. These wave functions are identical; to prevent confusion, the authors have adopted the allencompassing SCGVB name. Spin-Coupled Generalized Valence Bond Theory: New Perspectives on the Electronic Structure of Molecules and Chemical Bonds3 and recoupled pair bond dyad. 36 The SCGVB wave function describes molecules in terms of orbitals that are optimized at each geometry, allowing the atomic orbitals to change as a result of molecule formation. In addition to the changes in the orbitals, optimization of the general spin function used in the SCGVB wave function allows the spin function to change from that appropriate for the separated atoms or fragments to that appropriate for the molecule. SCGVB theory addresses a major limitation of RHF theory, providing an excellent zero-order description of molecules that require multiconfiguration descriptions, the making/breaking of bonds, and many chemical reactions and excited states. For most molecules, the SCGVB wave function captures the essential features of the FORS/CASSCF wave functions, with much reduced complexity compared to these latter wave functions.

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“…This quantity shows that the electron density at a given point in the space is determined by a Green’s function. This means that the electron density at r is defined as the sum of contributions of different local sources

, operating at all the other points of the space [ 52 , 53 ]. Therefore, the electron density can be written as in Equation (5)

where the local source, given by

, represents how the Laplacian of the electron density at the position

affects the electron density at a different position

[ 25 ].…”

Section: Models and Methodsmentioning

confidence: 99%

A Theoretical Study of the C–X Bond Cleavage Mediated by Cob(II)Aloxime

Seijas

Zambrano²,

Rodríguez³

et al. 2022

Molecules

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The C–X bond cleavage in different methyl halides (CH3X; X = Cl, Br, I) mediated by 5,6-dimethylbenzimidazole-bis(dimethylglyoximate)cobalt(II) (CoIICbx) was theoretically investigated in the present work. An SN2-like mechanism was considered to simulate the chemical process where the cobalt atom acts as the nucleophile and the halogen as the leaving group. The reaction path was computed by means of the intrinsic reaction coordinate method and analyzed in detail through the reaction force formalism, the quantum theory of atoms in molecules (QTAIM), and the calculation of one-electron density derived quantities, such as the source function (SF) and the spin density. A thorough comparison of the results with those obtained in the same reaction occurring in presence of 5,6-dimethylbenzimidazole-bis(dimethylglyoximate)cobalt(I) (CoICbx) was conducted to reveal the main differences between the two cases. The reactions mediated by CoIICbx were observed to be endothermic and possess higher activation energies in contrast to the reactions where the CoICbx complex is present. The latter was supported by the reaction force results, which suggest a relationship between the activation energy and the ionization potentials of the different nucleophiles present in the cleavage reaction. Moreover, the SF results indicates that the lower axial ligand (i.e., 5,6-dimethylbenzimidazole) exclusively participates on the first stage of the reaction mediated by the CoIICbx complex, while for the CoICbx case, it appears to have an important role along the whole process. Finally, the QTAIM charge analysis indicates that oxidation of the cobalt atom occurs in both cases; at the same time, it suggests the formation of an uncommon two-center one-electron bond in the CoIICbx case. The latter was confirmed by means of electron localization calculations, which resulted in a larger electron count at the Co–C interatomic region for the CoICbx case upon comparison with its CoIICbx counterpart.

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Revisiting ultra-weak metal-metal bonding

Cited by 13 publications

References 28 publications

Nature of the chemical bonding inD_3h[MH₃M]⁺cations (M = Be, Mg)

Nature of the chemical bonding inD_3h[MH₃M]⁺cations (M = Be, Mg)

Spin-Coupled Generalized Valence Bond Theory: New Perspectives on the Electronic Structure of Molecules and Chemical Bonds

A Theoretical Study of the C–X Bond Cleavage Mediated by Cob(II)Aloxime

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Revisiting ultra-weak metal-metal bonding

Cited by 13 publications

References 28 publications

Nature of the chemical bonding inD3h[MH3M]+cations (M = Be, Mg)

Nature of the chemical bonding inD3h[MH3M]+cations (M = Be, Mg)

Spin-Coupled Generalized Valence Bond Theory: New Perspectives on the Electronic Structure of Molecules and Chemical Bonds

A Theoretical Study of the C–X Bond Cleavage Mediated by Cob(II)Aloxime

Contact Info

Product

Resources

About

Nature of the chemical bonding inD_3h[MH₃M]⁺cations (M = Be, Mg)

Nature of the chemical bonding inD_3h[MH₃M]⁺cations (M = Be, Mg)