Pnictogen effects on the electronic interactions in the Lewis pair complexes Ph3EB(C6F5)3 (E = P, As, Sb)

Ketkov, Sergey Yu.; Kather, Ralf; Beckmann, Jens

doi:10.1016/j.jorganchem.2021.121944

Cited by 8 publications

(6 citation statements)

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“…The FLP-type structure B(C 6 F 4 ) 3 CF···P t Bu 3 is only 26 kJ mol –1 higher in energy than the DA complex B(C 6 F 4 ) 3 CF·P t Bu 3 and may be stabilized by interatomic contacts F···H of 2.18 Å. Similar stabilization via interaction between H atoms of phenyl and F atoms of C 6 F 5 groups was recently noted for the B(C 6 F 5 ) 3 ·EPh 3 complexes (E = As, Sb) by Ketkov et al Dissociation enthalpy of 25 kJ mol –1 and reorganization energies of the fragments (2.9 and 5.4 kJ mol –1 ) for B(C 6 F 4 ) 3 CF···P t Bu 3 are slightly larger compared to those for B(C 6 Me 4 ) 3 CH···P t Bu 3 . The entropy factor dissociation of these two weakly bound systems into components at 298 K is exergonic by 25–28 kJ mol –1 .…”

Section: Resultssupporting

confidence: 71%

Hydrogen Activation by Frustrated and Not So Frustrated Lewis Pairs Based on Pyramidal Lewis Acid 9-Boratriptycene: A Computational Study

Pomogaeva

Timoshkin

2022

ACS Omega

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Structural features and reactivity of frustrated Lewis pairs (FLPs) formed by pyramidal group 13 Lewis acids based on 9-bora and 9-alatriptycene and bulky phosphines P t Bu 3 , PPh 3 , and PCy 3 are considered at the M06-2X/def2-TZVP level of theory. Classic FLP is formed only in the B(C 6 Me 4 ) 3 CH/P t Bu 3 system, while both FLP and donor−acceptor (DA) complex are observed in the B(C 6 F 4 ) 3 CF/P t Bu 3 system. Formation of DA complexes was observed in other systems; the B(C 6 H 4 ) 3 CH•P t Bu 3 complex features an elongated DA bond and can be considered a "latent" FLP. Transition states and reaction pathways for molecular hydrogen activation have been obtained. Processes of heterolytic hydrogen splitting are energetically more favored in solution compared to the gas phase, while activation energies in the gas phase and in solution are close. The alternative processes of hydrogenation of B−C or Al−C bonds in the source pyramidal Lewis acids in the absence of a Lewis base are exergonic but have larger activation energies than those for heterolytic hydrogen splitting. The tuning of Lewis acidity of 9-boratriptycene by changing the substituents allows one to control its reactivity with respect to hydrogen activation. Interestingly, the most promising system from the practical point of view is the DA complex B(C 6 H 4 ) 3 CH•P t Bu 3 , which is predicted to provide both low activation energy and thermodynamic reversibility of the heterolytic hydrogen splitting process. It appears that such "not so frustrated" or "latent" FLPs are the best candidates for reversible heterolytic hydrogen splitting.

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Section: Resultssupporting

confidence: 71%

Hydrogen Activation by Frustrated and Not So Frustrated Lewis Pairs Based on Pyramidal Lewis Acid 9-Boratriptycene: A Computational Study

Pomogaeva

Timoshkin

2022

ACS Omega

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“…[68b] Thus, in contrast to recent Lewis acid/base repulsion model, proposed by Radius and Finze on the basis of the percent of buried volume, [73] specific interactions between bulky substituents may increase the dissociation energy of the complex. [67] We conclude, that reorganization energies of group 13 metal Lewis acids are 10-43 kJ mol À 1 , while they are significantly larger for the boron -containing Lewis acids (64-126 kJ mol À 1 ), which masks potentially high Lewis acidity of boron-containing LA. Group 14 element Lewis acids: Structural changes of group 14 element tetrahalides upon complex formation are much more diverse due to possibility of existence of several isomers for coordination numbers 5 and 6 (Scheme 7).…”

Section: Energetic Characteristics Of Da Complexes Importance Of the ...mentioning

confidence: 75%

“…More recently, Ketkov et al [67] pointed out, that in case of complexes bearing bulky terminal groups both on LA and LB, such as complexes B(C 6 F 5 ) 3 • EPh 3 (E = P, As, Sb), noncovalent interactions between terminal groups can provide the additional stabilization of the DA complex. In this case, the computed E DA value according to Equation ( 2) is not only the DA bond energy of the interacting central atoms of LA and LB, but has also a sizable contribution from the attractive interactions between bulky terminal groups.…”

Section: Energetic Characteristics Of Da Complexes Importance Of the ...mentioning

confidence: 99%

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The Field of Main Group Lewis Acids and Lewis Superacids: Important Basics and Recent Developments

Timoshkin

2023

Chemistry A European J

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New developments in the field of Lewis acidity are highlighted, with the focus of novel Lewis acids and Lewis superacids of group 2, 13, 14, and 15 elements. Several important basics, illustrated by modern examples (classification of Donor‐Acceptor (DA) complexes, amphoteric nature of any compound in terms of DA interactions, reorganization energies of main group Lewis acids and the role of the energies of frontier orbitals) are presented and discussed. It is emphasized that the Lewis acidity phenomena are general and play vital role in different areas of chemistry: from weak “atomophilic” interactions to the complexes of Lewis superacids.

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“…A class of reversible and dynamic noncovalent bonds that involve donor–acceptor interactions are Lewis pairs, in which the Lewis acid (LA) accepts an electron lone pair from the Lewis base (LB) to form a dative bond. , A distinctive feature of Lewis adducts is that the binding energy of the dative bond is tunable by electronic and steric modifications of the LA or the LB. , In a classic Lewis adduct involving boron trihydride and ammonia, the bond dissociation energy is estimated as 31 kcal/mol, which is approximately a third of the bond dissociation energy needed for a carbon–carbon single bond . Therefore, it is possible to tailor specific bond energies in Lewis adduct macromolecular systems to tune the properties of materials for specific applications such as sensors, gas storage, or catalysis .…”

Section: Introductionmentioning

confidence: 99%

Lewis Adduct-Induced Phase Transitions in Polymer/Solvent Mixtures

Hilaire

Mei

et al. 2021

ACS Polym. Au

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Functionalization-induced phase transitions in polymer systems in which a postpolymerization reaction drives polymers to organize into colloidal aggregates are a versatile method to create nanoscale structures with applications related to biomedicine and nanoreactors. Current functionalization methods to stimulate polymer self-assembly are based on covalent bond formation. Therefore, there is a need to explore alternative reactions that result in noncovalent bond formation. Here, we demonstrate that when the Lewis acid, tris(pentafluorophenyl) borane (BCF), is added to a solution containing poly(4-diphenylphosphino styrene) (PDPPS), the system will either macrophase-separate or form micelles if PDPPS is a homopolymer or a block in a copolymer, respectively. The Lewis adduct-induced phase transition is hypothesized to result from the favorable interaction between the PDPPS and BCF, which results in a negative interaction parameter (χ). A modified Flory–Huggins model was used to determine the predicted phase behavior for a ternary system composed of a polymer, a solvent, and a small molecule. The model indicates that there is a demixing region (i.e., macrophase separation) when the polymer and small molecule have favorable interactions (e.g., χ < 0) and that the phase separation region coincides well with the experimentally determined two-phase region for mixtures containing PDPPS, BCF, and toluene. The work presented here highlights that Lewis adduct-induced phase separation is a new approach to functionalization-induced self-assembly (FISA) and that ternary mixtures will undergo phase separation if two of the components exhibit a sufficiently negative χ.

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Pnictogen effects on the electronic interactions in the Lewis pair complexes Ph3EB(C6F5)3 (E = P, As, Sb)

Cited by 8 publications

References 46 publications

Hydrogen Activation by Frustrated and Not So Frustrated Lewis Pairs Based on Pyramidal Lewis Acid 9-Boratriptycene: A Computational Study

Hydrogen Activation by Frustrated and Not So Frustrated Lewis Pairs Based on Pyramidal Lewis Acid 9-Boratriptycene: A Computational Study

The Field of Main Group Lewis Acids and Lewis Superacids: Important Basics and Recent Developments

Lewis Adduct-Induced Phase Transitions in Polymer/Solvent Mixtures

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