Chemical Bonding in [Fe(η-P)] and Related Complexes.

Quantum chemical calculations of the six valence isoelectronic complexes [FeL], [CoL], and NiL with L = η-P, η-CH using density functional theory have been carried out. The molecular structures were investigated with a variety of methods. The analysis of the electronic structure in [Fe(η-P)] shows that the bonding situation is very similar to valence isoelectronic Ni(η-CH).

Breakdown of the Total Dipole Moments of Diatomic Molecules into Individual Orbital Contributions.

Quantum chemical results at the CCSD(T)/def2-QZVPP and BP86/def2-QZVPP levels are reported for the neutral and charged diatomic molecules EF, EO (E = B-Tl), EF, EO, EN (E = C-Pb), EO, and EN (E = N-Bi). The theoretically predicted bond lengths and dipole moments are in good agreement with each other and with the available experimental values. It is shown that the total dipole moment of the molecules can be nicely separated into the contributions of the individual occupied molecular orbitals.

Unusual quadruple bonds featuring collective interaction-type σ bonds between first octal-row atoms in the alkaline-earth compounds AeOLi (Ae = Be-Ba).

Quantum chemical calculations are reported for the complexes of alkaline earth metals AeOLi (Ae = Be-Ba) at the BP86-D3(BJ)/def2-QZVPP and CCSD(T)/def2-QZVPPQZVPP levels. The nature of the Ae-OLi bond has been analyzed with a variety of methods. The AeOLi molecules exhibit an unprecedented σ donor bond Ae→OLi where the ()s lone-pair electrons of the Ae atom are donated to vacant O-Li antibonding orbitals having the largest coefficient at lithium.

Silylene-Stabilized Neutral Dibora-Aromatics with a B═B Bond.

The unprecedented silylene-supported dibenzodiboraoxepin and 9,10-diboraphenanthrene complexes and were synthesized. The (NHSi)B(xanthene) [NHSi = PhC(NtBu)(MeN)Si:] results from debromination of the bis(NHSi)-stabilized bis(dibromoboryl)xanthene with potassium graphite (KC); is capable of activating white phosphorus and ammonia to form the BP cage compound and HN-B-B-H diborane species , respectively. The thermal rearrangement of affords the 9,10-dihydro-9,10-diboraphenanthrene through a bis(NHSi)-assisted intramolecular reductive C-O-C deoxygenation process.

Correction: Deciphering the chemical bonding of the trivalent oxygen atom in oxygen doped graphene.

[This corrects the article DOI: 10.1039/D4SC00142G.].

Deciphering the chemical bonding of the trivalent oxygen atom in oxygen doped graphene.

Recently, planar and neutral tricoordinated oxygen embedded in graphene has been imaged experimentally (, 2019, , 4570-4577). In this work, this unusual chemical species is studied utilizing a variety of state-of-the-art methods and combining periodic calculations with a fragmental approach. Several factors influencing the stability of trivalent oxygen are identified.

Multiple Bonding in AeN (Ae=Ca, Sr, Ba).

Quantum chemical calculations using ab initio methods at the MRCI+Q(8,9)/def2-QZVPPD and CCSD(T)/def2-QZVPPD levels as well as using density functional theory are reported for the diatomic molecules AeN (Ae=Ca, Sr, Ba). The anions CaN and SrN have electronic triplet (Π) ground states with nearly identical bond dissociation energies D ~57 kcal/mol calculated at the MRCI+Q(8,9)/def2-QZVPPD level. In contrast, the heavier homologue BaN has a singlet (Σ) ground state, which is only 1.

Mono-Ortho-Beryllated Carbodiphosphoranes: Synthesis, Structure, Bonding and Reactivity.

The reaction of organoberyllium compounds with hexaphenylcarbodiphosphorane yields mono-ortho-beryllated complexes, which feature a double dative Be=C bond. The bonding situation in these compounds together with a simple carbodiphosphorane and an N-heterocyclic carbene adduct was analysed with energy decomposition analysis in combination with natural orbital for chemical valence as well as with quantum theory of atoms-in-molecules. Furthermore, the driving forces accountable for mono-ortho-beryllation were elucidated along with the reactivity of the Be=C bond.

Stabilizing Monoatomic Two-Coordinate Bismuth(I) and Bismuth(II) Using a Redox Noninnocent Bis(germylene) Ligand.

The formation of isolable monatomic Bi complexes and Bi radical species is challenging due to the pronounced reducing nature of metallic bismuth. Here, we report a convenient strategy to tame Bi and Bi atoms by taking advantage of the redox noninnocent character of a new chelating bis(germylene) ligand. The remarkably stable novel Bi cation complex , supported by the new bis(iminophosphonamido-germylene)xanthene ligand [(P)Ge(Xant)Ge(P)] , [(P)Ge(Xant)Ge(P) = PhP(NBu)Ge(Xant)Ge(NBu)PPh, Xant = 9,9-dimethyl-xanthene-4,5-diyl], was synthesized by a two-electron reduction of the cationic BiI precursor complex with cobaltocene (CpCo) in a molar ratio of 1:2.

Analysis of the Unusual Chemical Bonds and Dipole Moments of AeF (Ae=Be-Ba): A Lesson in Covalent Bonding.

Quantum chemical calculations of the anions AeF (Ae=Be-Ba) have been carried out using ab initio methods at the CCSD(T)/def2-TZVPP level and density functional theory employing BP86 with various basis sets. The detailed bonding analyses using different charge- and energy partitioning methods show that the molecules possess three distinctively different dative bonds in the lighter species with Ae=Be, Mg and four dative bonds when Ae=Ca, Sr, Ba. The occupied 2p atomic orbitals (AOs) and to a lesser degree the occupied 2s AO of F donate electronic charge into the vacant sp(σ) and p(π) orbitals of Be and Mg which leads to a triple bond Ae F.

An all-metal fullerene: [K@AuSb].

The C fullerene molecule has attracted tremendous interest for its distinctive nearly spherical structure. By contrast, all-metal counterparts have been elusive: Fullerene-like clusters composed of noncarbon elements typically suffer from instability, resulting in more compact geometries that require multiple embedded atoms or external ligands for stabilization. In this work, we present the synthesis of an all-metal fullerene cluster, [K@AuSb], using a wet-chemistry method.

Stabilization of Cyclic C by Four Donor Ligands: A Theoretical Study of (L)C (L = Carbene).

Quantum chemical studies using density functional theory were carried out for the (L)C complexes with L = cAAC, DAC, NHC, SNHC, MIC1, and MIC2. The results show that the title complexes are highly stable with respect to dissociation, (L)C → C + 4L. However, their stability with respect to (L)C → 2(L)C is crucial for the assessment of their experimental viability.

On the σ-complex character of bis(gallyl)/digallane transition metal species.

σ-complexes of homoatomic E-E bonds are key intermediates in catalytically relevant oxidative addition reactions, but are as yet unknown for the group 13 elements. Here, stable species best described as σ-complexes of a 1,2-dichlorodigallane derivative with Ni and Pd are reported. They are readily accessed through the combination of a 1,2-dichlorodigallane derivative, which features chelating phosphine functionalities, with Ni and Pd synthons.

Diversification of the Carbodicarbene Class by Embedding an Anionic Component in its Scaffold.

Carbodicarbene (CDC) has become an emerging ligand in many fields due to its strong σ-donating ability. View Article and Find Full Text PDF

Structural Characterization and Bonding Analysis of [Hg{Fe(CO)}] [SbF].

The non-classical carbonyl complex [Hg{Fe(CO)}] [SbF] is prepared by reaction of Hg(SbF) and excess Fe(CO) in anhydrous HF. The single-crystal X-ray structure reveals a linear Fe-Hg-Fe moiety as well as an eclipsed conformation of the eight basal CO ligands. Interestingly, the Hg-Fe bond length of 2.

Aromaticity: Quo Vadis.

Aromaticity is one of the most deeply rooted concepts in chemistry. But why, if two-thirds of existing compounds can be classified as aromatic, is there no consensus on what aromaticity is? σ-, π-, δ-, spherical, Möbius, or all-metal aromaticity… why are so many attributes needed to specify a property? Is aromaticity a dubious concept? This perspective aims to reflect where the aromaticity community is and where it is going.

Genuine quadruple bonds between two main-group atoms. Chemical bonding in AeF (Ae = Be-Ba) and isoelectronic EF (E = B-Tl) and the particular role of d orbitals in covalent interactions of heavier alkaline-earth atoms.

Quantum chemical calculations of anions AeF (Ae = Be-Ba) and isoelectronic group-13 molecules EF (E = B-Tl) have been carried out using methods at the CCSD(T)/def2-TZVPP level and density functional theory employing BP86 various basis sets. The equilibrium distances, bond dissociation energies and vibrational frequencies are reported. The alkali earth fluoride anions AeF exhibit strong bonds between the closed-shell species Ae and F with bond dissociation energies between 68.

[Ga@Bi(NbMes)]: a linear Nb-Ga-Nb filament coordinated by a bismuth cage.

In this work, we report a low-valent Ga(I) complex, [Ga@Bi(NbMes)], with a linear Nb-Ga-Nb fragment, representing the first compound with Nb-Ga and Nb-Bi bonds. Quantum-chemical calculations reveal that the complex is an electron-precise cluster. The possible fragmentation pathway of the title cluster was studied by using electrospray ionization mass spectrometry and theoretical calculations.

Quest of Quadruple Bonding Between Two Main-Group Atoms in AeB and AeC (Ae=Ca, Sr, Ba) and the Role of d Orbitals of Heavier Alkaline-Earth Atoms in Covalent Interactions.

Quantum chemical calculations using ab initio methods at the MRCI+Q(6,8)/def2-QZVPP and CCSD(T)/def2-QZVPP levels as well as density functional theory are reported for the diatomic molecules AeB and isoelectronic AeC (Ae=Ca, Sr, Ba). The boride anions AeB have an electronic triplet ( Σ ) ground state. The quintet ( Σ ) state is 5.

Lewis Acid-Mediated Radical Stabilization and Dynamic Covalent Bonding: Tunable, Reversible and Photocontrollable.

This work describes a strategy not only to isolate a dynamically stable radical with physical property tunability, but to efficiently regulate the radical dissociation with reversibility and photo controllability. The addition of Lewis acid B(C F ) (BCF) into the solution of a radical σ-dimer (1-1) led to a stable radical (1⋅-2B), which has been characterized by EPR spectroscopy, UV/Vis spectroscopy and single crystal X-ray diffraction, in conjunction with theoretical calculation. The radical species is stabilized mainly by captodative effect, single electron transfer and steric effect.

Comment on "The oxidation state in low-valent beryllium and magnesium compounds" by M. Gimferrer, S. Danés, E. Vos, C. B. Yildiz, I. Corral, A. Jana, P. Salvador and D. M. Andrada, 2022, , 6583.

We challenge the assignment of the oxidation state +2 for beryllium and magnesium in the complexes Be(cAAC) and Mg(cAAC) as suggested by Gimferrer , 2022, , 6583 in a recent study. A careful review of the data in the ESI contradicts their own statement and shows that the results support the earlier suggestion that the metals are in the zero oxidation state. The authors reported wrong data for the excitation energies of Be and Mg to the D (np) state.

A Multidimensional Approach to Carbodiphosphorane-Bismuth Coordination Chemistry: Cationization, Redox-Flexibility, and Stabilization of a Crystalline Bismuth Hydridoborate.

Bismuth complexes stabilized by carbon-based donor ligands are underserved by their instability, often due to facile ligand dissociation and deleterious protonolysis. Herein, we show that the -bismuthination of hexaphenylcarbodiphosphorane enables a robust framework with geometrically constrained carbone-bismuth bonding interactions, which are highly tunable by cationization. The carbodiphosphorane bismuth halides ( and ) are remarkably air-stable and feature unprecedented C-Bi-X ligation, resulting in highly elongated Bi-X bonds.