Solvent selection for chemical reactions: automated computational screening of solvents using the SMD model

Dalessandro, Ellen V.; Pliego, Josefredo R.

doi:10.21577/0100-4042.20170224

Cited by 6 publications

(3 citation statements)

References 46 publications

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“…The rate has increased with increase in dielectric constant of the medium which indicates that the transition state through which the reaction take place is highly polar or charged, which is reported elsewhere in the case of quaternary salts [29][30]. Values of log k 2 against 1/D at 300 K are plotted and found to be linear (r = 0.9971) with a negative slope as given in figure 4 which once again confirms that the transition state is highly charge separated and polar.…”

Section: Fig 1: Plot Of Log Kobs Against Log C Table 1: Effect Of [Bc...supporting

confidence: 66%

Kinetics of Quaternization Between N, N-Dimethylaniline and Benzyl Chloride in Polar Solvents-a Revisit to Menshutkin Reaction

Bashpa,

Rajendran,

Bijudas

2021

JASR

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This work reports an extension of Menshutkin reaction and involves the studies on kinetics of quaternization reaction between N,N-Dimethylaniline and benzyl chloride in acetone and in other various solvents at 300 K. The progress of the reaction was followed by measuring the conductance of the product formed at regular intervals of time. The effect of [benzyl chloride] and [N,N-Dimethylaniline] on reaction rate was studied under pseudo-first order condition and the rate showed first order dependence on both [benzyl chloride] and [N,N-Dimethylaniline]. The effect of dielectric constant of the medium on reaction rate was studied by employing various solvents such as methyl ethyl ketone, isopropyl alcohol, ethyl alcohol, methyl alcohol and acetonitrile and the rate is found to increase with increase in dielectric constant of the medium. The linear plot with a negative slope on plotting log k2 against 1/D where D is the dielectric constant of the medium indicates the existence of a highly charged or a polar transition state during the progress of the reaction. The quaternization reaction was also carried out at different temperatures so as to compute the various thermodynamic parameters like activation energy, enthalpy of activation, entropy of activation and Gibb’s free energy change. The higher value of activation energy is attributed for a slower reaction which is sterically controlled rather than thermodynamically controlled. The negative value of entropy of activation (ΔS*) indicates some sort of surrendering of disorder in the transition state on its formation which proves that it is highly ordered with sufficient charge separation and polar in character. The product after purification was analysed by melting point and infra-red spectral analysis and is proved to be N-Benzyl-N,N-dimethylphenylmethanaminium chloride. A plausible mechanism in accordance with the obtained experimental results is reported.

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Section: Fig 1: Plot Of Log Kobs Against Log C Table 1: Effect Of [Bc...supporting

confidence: 66%

Kinetics of Quaternization Between N, N-Dimethylaniline and Benzyl Chloride in Polar Solvents-a Revisit to Menshutkin Reaction

Bashpa,

Rajendran,

Bijudas

2021

JASR

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“…The entire series of calculations were evaluated by density functional theory [ 22 ] (DFT) by Gaussian 16 program [ 23 ] and GaussView 6.0. The solvent environment was represented using the implicit solvent model (SMD) based on density [ 24 ]. The three different monomers, the allyl ethyl ether monomer (AEE), ethyl allyl amine monomer (EAA) and ethyl allyl sulfide monomer (EAS), were selected to represent allyl type compounds.…”

Section: Computational Detailsmentioning

confidence: 99%

DFT studies of solvent effect in hydrogen abstraction reactions from different allyl-type monomers with benzoyl radical

Zhao,

Li,

Lin

et al. 2023

BMC Chemistry

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Inert allyl-type monomers have been widely documented due to reduce degradation chain transfer. Recently, we and others discovered that the [3 + 2] cyclization reaction process by a photo-driven radical reaction, which can accelerate the polymerization. It was discovered that allyl ether monomers had much higher reactivity than other allyl monomers in the suspension photopolymerization initiated by Type I photoinitiator. Since the hydrogen abstraction reaction (HAR) is the initial step of cyclization, and in order to clarify the influence of solvents effect, three allyl-type monomers were employed, containing “O”, “N” and “S” atom as hydrogen donors. The benzoyl radical obtained from cleavage of photoinitiator was chosen as hydrogen acceptors. We explored the hydrogen abstraction reaction in different solvents (methanol, water and DMSO) by quantum chemistry for geometry and energy. An investigation was undertaken regarding the structural orbital by electrostatic potential (ESP) and topological analysis (ELF and LOL). The findings were also combined with the distortion model and transition state theory. We obtained the molecular interactions used independent gradient method in the Hirshfeld molecular density partition (IGMH). The Eckart’s correction allowed to examine the driving factors of the hydrogen abstraction reaction tunnels and these reactions constant rates are determined in the range of 500–2500 K depending on the modified Arrhenius form in different solvents effect. Our results can provide an answer for the different reactivities.

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“…[141][142][143] -justamente o que ocorre nas reações de estudo. Pode-se observar tal situação em todo o decorrer da reação com ouro (Figuras…”

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Estudo mecanístico da reação de hidrocloração de alquinos não ativados: perspectiva com e sem complexos de ouro(I)

Quilici¹

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The homogeneous catalysis by gold(I) complexes generally acts in an alkyne as substrate and occurs under a nucleophilic addition, forming the anti alkene as the product. First, a pre-catalysis step with silver salts is done, acting on LAuCl specie (where L is an organic ligand), which generates LAu + catalyst when breaking Au-Cl bond. Recently, the hydrochlorination reaction of alkynes catalyzed by gold(I) complexes was reported, under room temperature and open air, without the pre-catalysis step and possibly maintaining the Au-Cl bond all over the reaction course. This could be feasible by hydrogen bonds between HCl, HFIP (hexafluoroisopropanol) molecules and the inactive catalyst, LAuCl. Later, a new study, using a bromoalkyne as substrate, showed to be possible the alkene obtainment as a syn product, but without the presence of gold catalyst (or any other one). So, the gold presence leads the regioselectivity of the hydrochlorination of alkynes, resulting only the anti product. With Density Functional Theory (DFT), the reaction pathways were studied, with gold (LAu + ) and without it, aiming to understand the main aspects that drive the regioselectivity in the alkynes hydrochlorination reaction. The activation of LAuCl catalyst was studied either. In the regioselectivity case, the steric hindrance promoted by bromine atom guides the major formation of syn product, which transition state is 3 kcal.mol -1 more stable than the anti one. In the gold reaction, the metal is the responsible one for steric hindrance to the nucleophile, directing it to the anti position. Finally, in the LAuCl catalyzed reaction, HFIP molecule seems to be decisive to initiate the catalyst activation, by its interaction with the triple bond.

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Solvent selection for chemical reactions: automated computational screening of solvents using the SMD model

Cited by 6 publications

References 46 publications

Kinetics of Quaternization Between N, N-Dimethylaniline and Benzyl Chloride in Polar Solvents-a Revisit to Menshutkin Reaction

Kinetics of Quaternization Between N, N-Dimethylaniline and Benzyl Chloride in Polar Solvents-a Revisit to Menshutkin Reaction

DFT studies of solvent effect in hydrogen abstraction reactions from different allyl-type monomers with benzoyl radical

Estudo mecanístico da reação de hidrocloração de alquinos não ativados: perspectiva com e sem complexos de ouro(I)

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