scholarly journals Theoretical Study of the Microhydration of 1-Chloro and 2-Chloro Ethanol as a Clue for Their Relative Propensity Toward Dehalogenation

2018 ◽  
Author(s):  
George Petsis ◽  
Zoi Salta ◽  
Agnie M. Kosmas ◽  
Oscar Ventura
Keyword(s):  
Density Functional ◽  
Theoretical Study ◽  
Initial Step ◽  
Water Molecules ◽  
Water Solvent ◽  
Functional Methods ◽  
Electronic Distribution ◽  
Standard Reaction ◽  
Hydrogen Bonded

<p>This work reports a computational analysis of hydrogen bonded clusters of mono-, di-, tri- and tetra hydrates of the chlorohydrins CH<sub>3</sub>CHClOH (1ClEtOH) and CH<sub>2</sub>ClCH<sub>2</sub>OH (2ClEtOH). The goal of the study is to assess the role of the water solvent into the facilitation of the initial step for dehalogenation of these compounds, a process of interest in several contexts. Molecular orbital methods (MP2), density functional methods (B3LYP, M06 and wB97X-D) and composite model chemistries (CBS-QB3, G4) were employed to investigate the structure, electronic distribution and hydrogen-bonded structure of 7 monohydrates, 6 dihydrates, 5 trihydrates and 5 tetrahydrates of both species. Standard reaction enthalpy and standard Gibbs free reaction energy were computed for all aggregates with respect to <b><i>n</i></b> independent water molecules and with respect to the dimer, trimer and tetramer of water, respectively, in order to evaluate stability and hydrogen bonding network. The influence of the water chains on the length and vibrational frequencies, especially of the C-Cl and O-H bonds, was evaluated.</p>

scholarly journals Theoretical Study of the Microhydration of 1-Chloro and 2-Chloro Ethanol as a Clue for Their Relative Propensity Toward Dehalogenation

2018 ◽  
Author(s):  
George Petsis ◽  
Zoi Salta ◽  
Agnie M. Kosmas ◽  
Oscar Ventura
Keyword(s):  
Density Functional ◽  
Theoretical Study ◽  
Initial Step ◽  
Water Molecules ◽  
Water Solvent ◽  
Functional Methods ◽  
Electronic Distribution ◽  
Standard Reaction ◽  
Hydrogen Bonded

<p>This work reports a computational analysis of hydrogen bonded clusters of mono-, di-, tri- and tetra hydrates of the chlorohydrins CH<sub>3</sub>CHClOH (1ClEtOH) and CH<sub>2</sub>ClCH<sub>2</sub>OH (2ClEtOH). The goal of the study is to assess the role of the water solvent into the facilitation of the initial step for dehalogenation of these compounds, a process of interest in several contexts. Molecular orbital methods (MP2), density functional methods (B3LYP, M06 and wB97X-D) and composite model chemistries (CBS-QB3, G4) were employed to investigate the structure, electronic distribution and hydrogen-bonded structure of 7 monohydrates, 6 dihydrates, 5 trihydrates and 5 tetrahydrates of both species. Standard reaction enthalpy and standard Gibbs free reaction energy were computed for all aggregates with respect to <b><i>n</i></b> independent water molecules and with respect to the dimer, trimer and tetramer of water, respectively, in order to evaluate stability and hydrogen bonding network. The influence of the water chains on the length and vibrational frequencies, especially of the C-Cl and O-H bonds, was evaluated.</p>

Symmetry-adapted perturbation theory study for some magnesium complexes

2012 ◽  
Vol 90 (10) ◽  
pp. 819-827
Author(s):  
Mehdi D. Esrafili ◽  
Sirous Yourdkhani
Keyword(s):  
Perturbation Theory ◽  
Density Functional ◽  
Theoretical Study ◽  
Water Molecules ◽  
Interaction Energies ◽  
Unique Role ◽  
Functional Methods ◽  
Ligand Interactions ◽  
Good Agreement

A systematic theoretical study on Mg–ligand interactions has been carried out employing both ab initio correlated wave function and density functional methods. The interactions of the Mg(CH3N2)2 moiety with BF, CO, N2, NH3, and H2O ligands have been investigated by performing calculations at the B3LYP, MP2, MP4, and CCSD(T)/6–311++G(3df,3pd) levels of theory. Results indicate that the interaction energies of the Mg(CH3N2)2–L complexes increase in the order NH3 > H2O > BF > CO > N2. Symmetry-adapted perturbation theory (SAPT) analysis has been carried out to understand the nature of the forces involved in the bonding. The SAPT results indicate that the stabilities of the Mg–L interactions are attributed mainly to electrostatic effects, while induction and dispersion forces also play a significant role. The evaluated SAPT interaction energies for the Mg(CH3N2)2–L complexes are generally in good agreement with those obtained using the supermolecule CCSD(T) methods, suggesting that SAPT is a proper method to study the intermolecular interactions in these complexes. The results also suggest an explanation for the unique role of Mg2+ as a carrier of water molecules that mediate enzymatic hydrolysis reactions.

Substituent effect on N–H bond dissociation enthalpies of carbamates: a theoretical study

2015 ◽  
Vol 93 (3) ◽  
pp. 279-288 ◽  
Author(s):  
Rupinder preet Kaur ◽  
Damanjit Kaur ◽  
Ritika Sharma
Keyword(s):  
Substituent Effect ◽  
Density Functional ◽  
Theoretical Study ◽  
Natural Bond Orbital ◽  
Stabilization Energy ◽  
Isodesmic Reactions ◽  
Bond Dissociation ◽  
Density Functional Methods ◽  
Functional Methods ◽  
Orbital Analysis

The present investigation deals with the study of the N–H bond dissociation enthalpies (BDEs) of the Y-substituted (NH2-C(=X)Y-R) and N-substituted ((R)(H)NC(=X)YH) carbamates (X, Y = O, S, Se; R = H, CH3, F, Cl, NH2), which have been evaluated using ab initio and density functional methods. The variations in N−H BDEs of these Y-substituted and N-substituted carbamates as the effect of substituent have been understood in terms of molecule stabilization energy (ME) and radical stabilization energy (RE), which have been calculated using the isodesmic reactions. The natural bond orbital analysis indicated that the electrodelocalization of the lone pairs of heteroatoms in the molecules and radicals affect the ME and RE values depending upon the type and site of substitution (whether N- or Y-). The variations in N−H BDEs depend upon the combined effect of molecule stabilization and radical stabilization by the various substituents.

Role of crystallization water molecules on hydrogen-bonded structures and dielectric phase transitions in amino trimethylene phosphonic acid-based crystals

2017 ◽  
Vol 41 (12) ◽  
pp. 5142-5150 ◽  
Author(s):  
Yu-Ling Sun ◽  
Bei-Bei Zheng ◽  
Wen Zhang
Keyword(s):  
Phase Transitions ◽  
Water Molecule ◽  
Phosphonic Acid ◽  
Water Molecules ◽  
Crystallization Water Molecule ◽  
Crystallization Water ◽  
Organic Salts ◽  
Dielectric Phase ◽  
Hydrogen Bonded

Amino trimethylene phosphonic acid-based organic salts show crystallization water molecule-triggered dielectric transitions and relaxations.

A long lasting sunscreen controversy of 4-aminobenzoic acid and 4-dimethylaminobenzaldehyde derivatives resolved by ultrafast spectroscopy combined with density functional theoretical study

2020 ◽  
Vol 22 (15) ◽  
pp. 8006-8020
Author(s):  
Chris Tsz-Leung Chan ◽  
Chensheng Ma ◽  
Ruth Chau-Ting Chan ◽  
Hui-Min Ou ◽  
Han-Xin Xie ◽  
...  
Keyword(s):  
Molecular Mechanism ◽  
Density Functional ◽  
Ultrafast Spectroscopy ◽  
Theoretical Study ◽  
Pivotal Role ◽  
Aminobenzoic Acid ◽  
Sunscreen Agents

Photoprotection or photodamage: a pivotal role of water in regulating dynamics and molecular mechanism for efficacy of DMABA, DMAAP and PABA sunscreen agents.

THEORETICAL STUDY OF HYDROGEN BONDED CLUSTERS OF AMMONIA AND FULMINIC ACID

2008 ◽  
Vol 07 (02) ◽  
pp. 277-286 ◽  
Author(s):  
ABEDIEN ZABARDASTI ◽  
SAEID AMANI ◽  
MARYAM SALEHNASSAJ ◽  
ALI H. KIANFARD
Keyword(s):  
Ab Initio ◽  
Density Functional Calculations ◽  
Cluster Size ◽  
Density Functional ◽  
Theoretical Study ◽  
Cooperative Effect ◽  
Stabilization Energy ◽  
Topological Parameters ◽  
Hydrogen Bonded

Ab initio and density functional calculations are used to analyze the interaction between a molecule of fulminic acid with one, two, three, and four molecules of ammonia along with a 2:2 complex at B3LYP/6-311++G(d, p) and MP2/6-311++G(d, p) computational levels. Cooperative effect (CE) in terms of stabilization energy of clusters is calculated and discussed as well. For the studied clusters, the CE is increased with increasing cluster size. Red shifts of H – C stretching frequency for complexes involving HCNO as H -donor are predicted. Atom in molecules is used to analyze the cooperative effect on topological parameters.

Hydrogen-bonded molecular capsules: probing the role of water molecules in capsule formation in modified cyclotricatechylene

CrystEngComm ◽  
2017 ◽  
Vol 19 (32) ◽  
pp. 4759-4765 ◽  
Author(s):  
Giri Teja Illa ◽  
Sohan Hazra ◽  
Pardhasaradhi Satha ◽  
Chandra Shekhar Purohit
Keyword(s):  
Solid State ◽  
Water Molecules ◽  
Capsule Formation ◽  
Molecular Capsules ◽  
Pyridine Moiety ◽  
Hydrogen Bonded

Pyridine moiety-appended doubly bridged cyclotricatechylene (CTC(Py)2(OH)2) was synthesized and characterized. Solid state studies show that CTC(Py)2(OH)2 forms a capsular assembly in the presence of water but a polymeric assembly in its absence.

scholarly journals Theoretical study of thermoelectric properties of Y-doped Mg2Si using density functional methods

2012 ◽  
Vol 27 ◽  
pp. 109-114
Author(s):  
Wenhao Fan ◽  
Tao Zhang ◽  
Feng Zhang ◽  
Dehua Zhang ◽  
Qingsen Meng
Keyword(s):  
Thermoelectric Properties ◽  
Density Functional ◽  
Theoretical Study ◽  
Density Functional Methods ◽  
Functional Methods

Theoretical study of NHC-catalyzed C-S bond cleavage and reconstruction reaction: Mechanism, stereoselectivity, and role of catalyst

2021 ◽  
Author(s):  
Yang Wang ◽  
Yue Liu ◽  
Kaili Gong ◽  
Han Zhang ◽  
Yu Lan ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Reaction Mechanism ◽  
Density Functional ◽  
Theoretical Study ◽  
Bond Cleavage ◽  
Functional Theory

A theoretical study of the mechanism of the N-heterocyclic carbene (NHC)-catalyzed C-S bond cleavage and reconstruction reaction of unsaturated thioesters was conducted using density functional theory (DFT). The origin of...

Sign in / Sign up

Export Citation Format

Share Document