Spontaneous bond dissociation cascades induced by Ben clusters (n = 2,4)

2021 ◽  
Author(s):  
Eva Vos ◽  
Inés Corral ◽  
M. Merced Montero-Campillo ◽  
Otilia Mó ◽  
José Elguero ◽  
...  
Keyword(s):  
Lewis Acids ◽  
Lewis Bases ◽  
Bond Dissociation ◽  
Multireference Methods

Be4 clusters are very powerful Lewis acids leading to the total dissociation of all the bonds of the Lewis bases interacting with them. The product of the bond dissociation cascade possesses a hyper-coordinated center. Multireference methods are needed to correctly describe these complexes.

Building new discrete supramolecular assemblies through the interaction of iso-tellurazole N-oxides with Lewis acids and bases

2017 ◽  
Vol 203 ◽  
pp. 187-199 ◽  
Author(s):  
Peter C. Ho ◽  
Hilary A. Jenkins ◽  
James F. Britten ◽  
Ignacio Vargas-Baca
Keyword(s):  
Electron Acceptor ◽  
Lewis Acids ◽  
Heterocyclic Carbenes ◽  
Supramolecular Assemblies ◽  
Triphenyl Phosphine ◽  
Tellurium Atom ◽  
Lewis Bases ◽  
Acids And Bases ◽  
Lewis Acids And Bases

The supramolecular macrocycles spontaneously assembled by iso-tellurazole N-oxides are stable towards Lewis bases as strong as N-heterocyclic carbenes (NHC) but readily react with Lewis acids such as BR3 (R = Ph, F). The electron acceptor ability of the tellurium atom is greatly enhanced in the resulting O-bonded adducts, which consequently enables binding to a variety of Lewis bases that includes acetonitrile, 4-dimethylaminopyridine, 4,4′-bipyridine, triphenyl phosphine, a N-heterocyclic carbene and a second molecule of iso-tellurazole N-oxide.

Pyridinediimine Iron Dicarbonyl Complexes with Pendant Lewis Bases and Lewis Acids Located in the Secondary Coordination Sphere

2013 ◽  
Vol 2013 (22-23) ◽  
pp. 4008-4015 ◽  
Author(s):  
Zachary Thammavongsy ◽  
Micah E. LeDoux ◽  
Andrew G. Breuhaus-Alvarez ◽  
Takele Seda ◽  
Lev N. Zakharov ◽  
...  
Keyword(s):  
Coordination Sphere ◽  
Lewis Acids ◽  
Lewis Bases ◽  
Secondary Coordination Sphere

scholarly journals Non-Covalent Interactions Involving Alkaline-Earth Atoms and Lewis Bases B: An ab Initio Investigation of Beryllium and Magnesium Bonds, B···MR2 (M = Be or Mg, and R = H, F or CH3)

Inorganics ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 35 ◽  
Author(s):  
Ibon Alkorta ◽  
Anthony Legon
Keyword(s):  
Ab Initio ◽  
Lewis Acids ◽  
Alkaline Earth ◽  
Basis Set ◽  
Covalent Bonds ◽  
Lewis Bases ◽  
Complete Basis Set ◽  
Definition Of ◽  
The Individual ◽  
Equilibrium Dissociation

Geometries, equilibrium dissociation energies (De), intermolecular stretching, and quadratic force constants (kσ) determined by ab initio calculations conducted at the CCSD(T)/aug-cc-pVTZ level of theory, with De obtained by using the complete basis set (CBS) extrapolation [CCSD(T)/CBS energy], are presented for the B···BeR2 and B···MgR2 complexes, where B is one of the following Lewis bases: CO, H2S, PH3, HCN, H2O or NH3, and R is H, F or CH3. The BeR2 and MgR2 precursor molecules were shown to be linear and non-dipolar. The non-covalent intermolecular bond in the B···BeR2 complexes is shown to result from the interaction of the electrophilic band around the Be atom of BeR2 (as indicated by the molecular electrostatic potential surface) with non-bonding electron pairs of the base, B, and may be described as a beryllium bond by analogy with complexes such as B···CO2, which contain a tetrel bond. The conclusions for the B···MgR2 series are similar and a magnesium bond can be correspondingly invoked. The geometries established for B···BeR2 and B···MgR2 can be rationalized by a simple rule previously enunciated for tetrel-bonded complexes of the type B···CO2. It is also shown that the dissociation energy, De, is directly proportional to the force constant, kσ, in each B···MR2 series, but with a constant of proportionality different from that established for many hydrogen-bonded B···HX complexes and halogen-bonded B···XY complexes. The values of the electrophilicity, EA, determined from the De for B···BeR2 complexes for the individual Lewis acids, A, reveal the order A = BeF2 > BeH2 > Be(CH3)2—a result that is consistent with the −I and +I effects of F and CH3 relative to H. The conclusions for the MgR2 series are similar but, for a given R, they have smaller electrophilicities than those of the BeR2 series. A definition of alkaline-earth non-covalent bonds is presented.

scholarly journals Recent Synthesis Developments of Organoboron Compounds via Metal-Free Catalytic Borylation of Alkynes and Alkenes

Molecules ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. 101 ◽  
Author(s):  
Yanmei Wen ◽  
Chunmei Deng ◽  
Jianying Xie ◽  
Xinhuang Kang
Keyword(s):  
Lewis Acids ◽  
Heterocyclic Carbenes ◽  
Lewis Base ◽  
Organoboron Compounds ◽  
Lewis Bases ◽  
Metal Free ◽  
Recent Synthesis

Diboron reagents have been traditionally regarded as “Lewis acids”, which can react with simple Lewis base to create a significant nucleophilic character in one of boryl moieties. In particular, bis(pinacolato)diboron (B2pin2) reacts with simple Lewis bases, such as N-heterocyclic carbenes (NHCs), phosphines and alkoxides. This review focuses on the application of trivalent nucleophilic boryl synthon in the selective preparation of organoboron compounds, mainly through metal-free catalytic diboration and the β-boration reactions of alkynes and alkenes.

On the behaviour of biradicaloid [P(μ-NTer)]2 towards Lewis acids and bases

2016 ◽  
Vol 52 (37) ◽  
pp. 6328-6331 ◽  
Author(s):  
Alexander Hinz ◽  
Axel Schulz ◽  
Alexander Villinger
Keyword(s):  
Lewis Acids ◽  
Heterocyclic Carbenes ◽  
Chloride Complexes ◽  
Lewis Bases ◽  
Acids And Bases ◽  
Lewis Acids And Bases

The well-known diphosphadiazane-1,3-diyl [P(μ-NTer)]2 (Ter = 2,6-bis(2,4,6-trimethyl-phenyl)-phenyl) was treated with Lewis bases such as N-heterocyclic carbenes and Lewis acids e.g. gold(i) chloride complexes.

Biological control of S-nitrosothiol reactivity: potential role of sigma-hole interactions

2020 ◽  
Vol 22 (12) ◽  
pp. 6595-6605
Author(s):  
Niloufar Hendinejad ◽  
Qadir K. Timerghazin
Keyword(s):  
Nitric Oxide ◽  
Biological Control ◽  
Hydrogen Bonding ◽  
Lewis Acids ◽  
Potential Role ◽  
Lewis Bases ◽  
Sigma Hole ◽  
Derivatives Of

S-Nitrosothiols, ubiquitous biological derivatives of nitric oxide, can engage in σ-hole/bonding with Lewis bases, which, in combination with hydrogen bonding with Lewis acids, could be the basis of enzymatic control of S-nitrosothiol reactions.

Bidentate Chiral Bis(imidazolium)-Based Halogen Bond Donors: Synthesis and First Applications in Enantioselective Recognition and Catalysis

2019 ◽  
Author(s):  
Revannath L. Sutar ◽  
Elric Engelage ◽  
Raphael Stoll ◽  
Stefan Huber
Keyword(s):  
Lewis Acids ◽  
Chiral Recognition ◽  
Halogen Bond ◽  
Halogen Bonding ◽  
Noncovalent Interaction ◽  
Asymmetric Induction ◽  
Nmr Studies ◽  
Lewis Bases ◽  
First Case ◽  
Mukaiyama Aldol

Even though halogen bonding – the noncovalent interaction between electrophilic halogen substituents and Lewis bases – has now been established in molecular recognition and catalysis, its use in enantioselective processes is still very little explored. Herein, we present the synthesis of chiral bidentate halogen bond donors based on two iodoimidazolium units with rigidly attached chiral sidearms. With these Lewis acids, chiral recognition of a racemic diamine is achieved in NMR studies. DFT calculations support a 1:1 interaction of the halogen bond donor with both enantiomers and indicate that the chiral recognition is based on a different spatial orientation of the Lewis bases in the halogen bonded complexes. In addition, moderate enantioselectivity is achieved in a Mukaiyama aldol reaction with a preorganized variant of the chiral halogen bond donor. This represents the first case in which asymmetric induction was realized with a pure halogen bond donor lacking any additionally active functional groups.

The bond dissociation energies of SO3—X– (X = F, Cl, Br, and I)

2005 ◽  
Vol 83 (11) ◽  
pp. 2013-2019 ◽  
Author(s):  
Changtong Hao ◽  
Thomas M Gilbert ◽  
Lee S Sunderlin
Keyword(s):  
Gas Phase ◽  
Lewis Acids ◽  
Basis Sets ◽  
Collision Induced Dissociation ◽  
Bond Dissociation Energies ◽  
Flowing Afterglow ◽  
Bond Dissociation ◽  
Dissociation Energies ◽  
Upper Limit ◽  
Bond Strengths

The gas-phase strengths of the SO3—X- bonds (X = Cl, Br, and I) have been determined to be 222 ± 13, 179 ± 11, and 161 ± 9 kJ/mol, respectively, by measuring thresholds for collision-induced dissociation in a flowing afterglow-tandem mass spectrometer. An upper limit of D(SO3—F–) ≤ 488 ± 19 kJ/mol was also determined. The periodic trends in the halide affinities of SO3 closely parallel those for SO2 and other Lewis acids. Bond strengths computed using the B3LYP, MP2, QCISD(T), and other models with several basis sets are generally lower than experiment.Key words: bond dissociation energies, computational chemistry, Lewis acids, superacids, halide affinities.

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