Enthalpies of formation and bond energies in lithium, beryllium, and boron derivatives. A theoretical attempt for data rationalization

Sana, M.; Leroy, Georges; Wilante, Claude

doi:10.1021/om00047a059

Cited by 39 publications

(24 citation statements)

References 4 publications

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“…In agreement with previous theoretical studies, [27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42] BeH 2 is calculated to have a linear, centrosymmetric structure. However, the present best estimate for D 0 (34.8 kcal/ mol) is somewhat lower than most previous theoretical estimates.…”

Section: Discussionsupporting

confidence: 88%

σ Bond Activation by Cooperative Interaction with ns² Atoms: Be + nH₂, n = 1−3

Sharp

Gellene

2000

J. Phys. Chem. A

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Ab initio investigations at the MP2, CCSD(T), and MRCISD levels of theory with augmented triple-basis sets have identified and characterized various stationary points on the Be/(H 2 ) n , n ) 1-3, hypersurfaces. The van der Waals complexes, Be(H 2 ) n , are very weakly bound (D e ) 0.08-0.32 kcal/mol with respect to H 2 loss) with H 2 /H 2 interactions playing an important role in determining equilibrium structures which can be understood in terms of the various relevant long-range potentials. The covalent molecule, BeH 2 , is found to have a linear, centrosymmetric structure and to be strongly bound with respect to Be + H 2 , in agreement with previous calculations. BeH 2 interacts weakly with additional H 2 molecules (D e < 0.75 kcal/mol) which are positioned parallel to the near-linear BeH 2 moiety in the equilibrium structures of the BeH 2 (H 2 ) n-1 complexes. Of particular interest is the dramatic change in the nature of the transition state for BeH 2 production depending on the number of H 2 molecules present. For n ) 1, the reaction proceeds stepwise: first breaking the H 2 bond and forming one BeH bond followed by forming the second BeH bond. This process has an activation energy of about 56 kcal/mol. For n ) 2, the reaction proceeds via a pericyclic mechanism through a planar cyclic transition state where two H 2 bonds are broken while simultaneously two BeH bonds and one new H 2 bond are formed. The activation energy for this process decreases from the n ) 1 value to about 38 kcal/mol. For n ) 3, the reaction proceeds through a true insertion mechanism with the addition of the third H 2 molecule, decreasing the activation energy to about 33 kcal/mol. The results are discussed in comparison to the isoelectronic B + /nH 2 systems where significant σ bond activation through a cooperative interaction mechanism has been identified.

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Section: Discussionsupporting

confidence: 88%

σ Bond Activation by Cooperative Interaction with ns² Atoms: Be + nH₂, n = 1−3

Sharp

Gellene

2000

J. Phys. Chem. A

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“…The B‐O‐C linkage of boronate esters is thermodynamically highly stable 11. Yet, boronate esters are dynamic compounds that undergo rapid exchange reactions, for example, with alcohols.…”

Section: Resultsmentioning

confidence: 99%

Borophosphonate Cages: Easily Accessible and Constitutionally Dynamic Heterocubane Scaffolds

Tönnemann¹,

Scopelliti²,

Zhurov³

et al. 2012

Chemistry A European J

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A versatile and experimentally facile procedure for the synthesis of borophosphonate cages of the general formula [tBuPO(3)BR'](4) is described. The method involves heating of tert-butylphosphonic acid with a boronic acid in toluene to give borophosphonates in [4+4] condensation reactions. The products display a heterocubane structure with bent P-O-B bridges as evidenced by crystallographic analyses. Scrambling experiments show that the borophosphonate cages are constitutionally dynamic scaffolds with exchange reactions occurring on the hour time scale at room temperature. The cages can be decorated with reactive groups such as aldehydes. Our results demonstrate that borophosphonate cages are interesting building blocks for dynamic covalent chemistry.

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“… 18 Perhaps the main criticism of any of the covalently bonded models (model i or iv, see Section 1 ) is by Mercier et al: 11 they posit that because the pore size swells up to 15.4 Å when in water, the DBA cannot be covalently linked as 12 Å would be the limit of the height. 11 However, an alternative explanation for the large swelling when flooded with a polar solvent may be boronate esterification, a well-studied reversible reaction 49 , 50 where a boron bonded to two oxygen and a diol, in this case carbon, will have its oxygens detach from a surface such as graphene in the presence of water, leaving behind OH on the surface as the boron’s two newly detached oxygens each gain a hydrogen, all within a short time. 50 When the boronate’s oxygens bond back with the surface, the reaction produces water.…”

Section: Discussionmentioning

confidence: 99%

“… 11 However, an alternative explanation for the large swelling when flooded with a polar solvent may be boronate esterification, a well-studied reversible reaction 49 , 50 where a boron bonded to two oxygen and a diol, in this case carbon, will have its oxygens detach from a surface such as graphene in the presence of water, leaving behind OH on the surface as the boron’s two newly detached oxygens each gain a hydrogen, all within a short time. 50 When the boronate’s oxygens bond back with the surface, the reaction produces water. If no water is present, the boronate remains bonded to the surface.…”

Section: Discussionmentioning

confidence: 99%

Adsorption-Induced Expansion of Graphene Oxide Frameworks with Covalently Bonded Benzene-1,4-diboronic Acid: Numerical Studies

et al. 2022

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Graphene oxide frameworks (GOFs) are interesting adsorbent materials with well-defined slit-shaped pores of almost monodisperse separation of ∼1 nm between graphene-like layers; however, the exact nature of the structure has remained undetermined. Recently, GOFs were observed to swell monotonically upon the adsorption of methane and xenon under supercritical conditions. Here, we present the results of molecular dynamics simulations of the adsorption of methane and xenon for various proposed GOF structures based upon force fields based on ab initio B3LYP density functional theory calculations. The simulations reproduce well both the adsorption isotherms and the expansion of the interlayer spacing for methane and xenon for a model of GOFs formed by covalently bonded benzene-1,4-diboronic acid oriented at quasirandom angles with respect to the graphene layers.

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Enthalpies of formation and bond energies in lithium, beryllium, and boron derivatives. A theoretical attempt for data rationalization

Cited by 39 publications

References 4 publications

σ Bond Activation by Cooperative Interaction with ns² Atoms: Be + nH₂, n = 1−3

σ Bond Activation by Cooperative Interaction with ns² Atoms: Be + nH₂, n = 1−3

Borophosphonate Cages: Easily Accessible and Constitutionally Dynamic Heterocubane Scaffolds

Adsorption-Induced Expansion of Graphene Oxide Frameworks with Covalently Bonded Benzene-1,4-diboronic Acid: Numerical Studies

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Enthalpies of formation and bond energies in lithium, beryllium, and boron derivatives. A theoretical attempt for data rationalization

Cited by 39 publications

References 4 publications

σ Bond Activation by Cooperative Interaction with ns2 Atoms: Be + nH2, n = 1−3

σ Bond Activation by Cooperative Interaction with ns2 Atoms: Be + nH2, n = 1−3

Borophosphonate Cages: Easily Accessible and Constitutionally Dynamic Heterocubane Scaffolds

Adsorption-Induced Expansion of Graphene Oxide Frameworks with Covalently Bonded Benzene-1,4-diboronic Acid: Numerical Studies

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σ Bond Activation by Cooperative Interaction with ns² Atoms: Be + nH₂, n = 1−3

σ Bond Activation by Cooperative Interaction with ns² Atoms: Be + nH₂, n = 1−3