The nature of the C–As bonds in arsaalkynes: an atoms in molecules and electron localization function study

Enzymatic hydrolysis is the main target to deal with ACh depletion. However, a recent study indicates that the nonenzymatic one may contribute to the depletion. This study highlights the necessity of considering possible conformers, discrete-continuum models, and dispersive effects for investigating the neutral (non-enzymatic) hydrolysis of flexible molecules in aqueous solution. We systematically built the possible conformers within the first-principles framework. The results confirm the reactivity of high-energy ACh conformer towards neutral hydrolysis. We proposed that conformational changes occur before the hydrolysis. The calculated activation and reaction energy shows that the discrete-continuum solvation model gives the closest result to experimental observations. This study also shows that neglecting dispersive effects brings unreliable structures in the initial state, which leads to unreliable activation energy.

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“…[42]. A detailed study of method assessments for low‐energy conformers has been demonstrated by Bun Chan [47] …”

Section: Resultsmentioning

confidence: 99%

“…A detailed study of method assessments for low-energy conformers has been demonstrated by Bun Chan. [47] The energetic analysis of this work mainly concerns on the low-(ttg) and high-energy conformers (ctg and ctt). The span of the conformers' energy was at least 4.8 kcal/mol.…”

Section: The Previous Conformational Studiesmentioning

confidence: 99%

Acetylcholine Conformational Flexibility and Its Neutral Hydrolysis in Aqueous Solution

et al. 2023

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“…Similarly, it is known that the ''nearsightedness'' of the off-diagonal terms in the first-order density matrix increases as the band gap increases. [14][15][16][17] The problem with these forms is that they require non-local information and this means that the connexion with real space (molecular structure, bonds and dihedral angles) is lost. Several local indicators have been recently proposed in the literature.…”

Section: Introductionmentioning

confidence: 99%

Understanding conductivity in molecular switches: a real space approach in octaphyrins

Woller

Ramos‐Berdullas

Mandado

et al. 2016

Phys. Chem. Chem. Phys.

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In recent years, expanded porphyrins have emerged as a promising class of π-conjugated molecules that display unique electronic, optical and conformational properties. Several expanded porphyrins can switch between planar and twisted conformations, which have different photophysical properties. Such a change of topology involves a Hückel-Möbius aromaticity switch in a single molecule and it can be induced by solvent, pH and metallation. These features make expanded porphyrins suitable for the development of a novel type of molecular switches for molecular electronic devices. Octaphyrins consisting of eight pyrrole rings, exhibit twisted-Hückel, Möbius and Hückel π-conjugation topologies depending on the oxidation and protonation state, with distinct electronic structures and aromaticity. Our working hypothesis is that a significant change in the conductance of expanded porphyrins will be observed after the topology switching. Despite the potential of Hückel-Möbius systems as conductance switches, the relationship between the conductance and the molecular topology is not yet understood. We have explored the performance of local descriptors of conductivity in simple molecules, as well as the relationship with conductance. Since these indexes provide a qualitative measure of delocalization and conductance in the probe molecules, we have carried out a local analysis of electrical conductance changes as a function of the π-conjugation in two examples. In one of them, the locality of the electronic changes ensures the ability of these indexes to describe the conductance as local. Moreover, it enables to identify which conformational switch would be more efficient from an electronic device perspective. However, we also show that it is not always possible to reduce conductance changes to one bond, and in those molecules where a deep rearrangement occurs far from the structural perturbation, local measures show a limited efficiency. This is a first step for the description of the connection between the molecular structure and conductance in molecular switches.

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Cyaarside (CAs⁻) and 1,3‐Diarsaallendiide (AsCAs²⁻) Ligands Coordinated to Uranium and Generated via Activation of the Arsaethynolate Ligand (OCAs⁻)

et al. 2019

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Reaction of the trivalent uranium complex [((Ad,MeArO)3N)U(DME)] with one molar equiv [Na(OCAs)(dioxane)3], in the presence of 2.2.2‐crypt, yields [Na(2.2.2‐crypt)][{((Ad,MeArO)3N)UIV(THF)}(μ‐O){((Ad,MeArO)3N)UIV(CAs)}] (1), the first example of a coordinated η1‐cyaarside ligand (CAs−). Formation of the terminal CAs− is promoted by the highly reducing, oxophilic UIII precursor [((Ad,MeArO)3N)U(DME)] and proceeds through reductive C−O bond cleavage of the bound arsaethynolate anion, OCAs−. If two equiv of OCAs− react with the UIII precursor, the binuclear, μ‐oxo‐bridged U2IV/IV complex [Na(2.2.2‐crypt)]2[{((Ad,MeArO)3N)UIV}2(μ‐O)(μ‐AsCAs)] (2), comprising the hitherto unknown μ:η1,η1‐coordinated (AsCAs)2− ligand, is isolated. The mechanistic pathway to 2 involves the decarbonylation of a dimeric intermediate formed in the reaction of 1 with OCAs−. An alternative pathway to complex 2 is by conversion of 1 via addition of one further equiv of OCAs−.

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The nature of the C–As bonds in arsaalkynes: an atoms in molecules and electron localization function study

Cited by 10 publications

References 56 publications

Acetylcholine Conformational Flexibility and Its Neutral Hydrolysis in Aqueous Solution

Acetylcholine Conformational Flexibility and Its Neutral Hydrolysis in Aqueous Solution

Understanding conductivity in molecular switches: a real space approach in octaphyrins

Cyaarside (CAs⁻) and 1,3‐Diarsaallendiide (AsCAs²⁻) Ligands Coordinated to Uranium and Generated via Activation of the Arsaethynolate Ligand (OCAs⁻)

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The nature of the C–As bonds in arsaalkynes: an atoms in molecules and electron localization function study

Cited by 10 publications

References 56 publications

Acetylcholine Conformational Flexibility and Its Neutral Hydrolysis in Aqueous Solution

Acetylcholine Conformational Flexibility and Its Neutral Hydrolysis in Aqueous Solution

Understanding conductivity in molecular switches: a real space approach in octaphyrins

Cyaarside (CAs−) and 1,3‐Diarsaallendiide (AsCAs2−) Ligands Coordinated to Uranium and Generated via Activation of the Arsaethynolate Ligand (OCAs−)

Contact Info

Product

Resources

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Cyaarside (CAs⁻) and 1,3‐Diarsaallendiide (AsCAs²⁻) Ligands Coordinated to Uranium and Generated via Activation of the Arsaethynolate Ligand (OCAs⁻)