Theoretical Study of Substituent Effects on Geometric and Spectroscopic Parameters (IR,13C,29Si NMR) and Energy Decomposition Analysis of the Bonding in Molybdenum Silylidyne Complexes CpMo(CO)2(≡Si-para-C6H4X)

2017 ◽  
Vol 64 (5) ◽  
pp. 522-530 ◽  
Author(s):  
Hadis Ghobadi ◽  
Reza Ghiasi ◽  
Saeid Jamehbozorgi
2021 ◽  
Author(s):  
Qiang Zhao

Abstract The σ···π interactions in the Au6···PhX (X=H, CH3, OH, OCH3, NH2, F, Cl, Br, CN, NO2) complexes are studied using quantum chemical methods. The present study focuses on the different effects of electron-donating and -withdrawing substituent. The structure and binding strength of the complexes are examined. The interactions between Au6 cluster and various substituted benzene become strengthened relative to the Au6···benzene complex. The interaction region indicator analysis was performed, and the interaction region and interaction between the substituent and Au6 cluster are discussed. It is found that the substituent effects on the σ···π interactions between Au6 cluster and substituted benzene are different from π···π interactions of benzene dimer. Energy decomposition analysis was carried out to study the nature of σ···π interactions, and the substituent effects are mainly reflected on the electrostatic interaction and dispersion.


2020 ◽  
Author(s):  
Yuezhi Mao ◽  
Matthias Loipersberger ◽  
Kareesa Kron ◽  
Jeffrey Derrick ◽  
Christopher Chang ◽  
...  

<p>To facilitate computational investigation of intermolecular interactions in the solution phase, we report the development of ALMO-EDA(solv), a scheme that allows the application of continuum solvent models within the framework of energy decomposition analysis (EDA) based on absolutely localized molecular orbitals (ALMOs). In this scheme, all the quantum mechanical states involved in the variational EDA procedure are computed with the presence of solvent environment so that solvation effects are incorporated in the evaluation of all its energy components. After validation on several model complexes, we employ ALMO-EDA(solv) to investigate substituent effects on two classes of complexes that are related to electrochemical CO<sub>2</sub> reduction catalysis. For [FeTPP(CO<sub>2</sub>−κC)]<sup>2−</sup> (TPP = tetraphenylporphyrin), we reveal that two ortho substituents which yield most favorable CO2 binding, −N(CH<sub>3</sub>)<sub>3</sub><sup>+</sup> (TMA) and −OH, stabilize the complex via through-structure and through-space mechanisms, respectively. The Coulombic interaction between the positively charged TMA group and activated CO<sub>2</sub> is found to be largely attenuated by the polar solvent. Furthermore, we also provide computational support for the design strategy of utilizing bulky, flexible ligands to stabilize activated CO<sub>2</sub> via long-range Coulomb interactions, which creates biomimetic solvent-inaccessible “pockets” in that electrostatics is unscreened. For the reactant and product complexes associated with the electron transfer from the <i>p</i>-terphenyl radical anion to CO<sub>2</sub> , we demonstrate that the double terminal substitution of <i>p</i>-terphenyl by electron-withdrawing groups considerably strengthens the binding in the product state while moderately weakens that in the reactant state, which are both dominated by the substituent tuning of the electrostatics component. These applications illustrate that this new extension of ALMO-EDA provides a valuable means to unravel the nature of intermolecular interactions and quantify their impacts on chemical reactivity in solution.<br></p>


2009 ◽  
Vol 87 (7) ◽  
pp. 1074-1080 ◽  
Author(s):  
Carles Acosta-Silva ◽  
Òscar González-Blanco ◽  
Vicenç Branchadell

The hetero-Diels–Alder reactions of butadiene with Fe(CO)3-coordinated formylbutadiene and formyltrimethylenemethane catalyzed by Lewis acids have been theoretically studied through density functional calculations. The results obtained show that, for the reaction with (formylbutadiene)Fe(CO)3, the kinetically most favourable product is the one corresponding to the attack of butadiene on the s-cis conformer of the formylbutadiene fragment when the reaction is catalyzed by BF3, and the one corresponding to the attack on the s-trans conformer when the catalyst is TiCl4. On the other hand, for the reaction with (formyltrimethylenemethane)Fe(CO)3 catalyzed by BF3, the product corresponding to the attack on the s-trans conformer is predicted to be favoured. These results have been interpreted through an energy decomposition analysis of the potential-energy barriers.


2016 ◽  
Vol 15 (04) ◽  
pp. 1650032 ◽  
Author(s):  
Mehdi Bayat ◽  
Fatemeh Amraie ◽  
Sadegh Salehzadeh

A theoretical study on the structure, formation and nature of E–E and C–E bonds (E[Formula: see text][Formula: see text][Formula: see text]Si, Ge, Sn) in catenated compounds of the group 14 elements including disila-, digerma- and distannacyclobutene ring formed from the reaction of 1-thiacyclohept-4-yne and E(NR)2SiR2 molecules [E[Formula: see text][Formula: see text][Formula: see text]Si, Ge, Sn, R[Formula: see text][Formula: see text][Formula: see text]t-Bu, H, F, Cl, Br] in 1:2 mole ratio has been investigated at the M06/def2-TZVPP level of theory. The results showed that the formation energy of the products of the reaction above with Si(NBr)2SiBr2 and Sn(NF)2SiF2 reactants has greatest and the smallest value, respectively. In agreement with the values of formation energies, both the calculated Wiberg bond indices (WBI) for E—E and C—E bonds and [Formula: see text](BCP) of E—E bond in the products of two above reactants have largest and smallest values, respectively. The nature of E—E bond in the products was also studied with atoms in molecules (AIM) and natural bond orbital (NBO) analyses. The data confirmed that the E—E bond is partly covalent. In addition, the nature of C—E bond was investigated with energy decomposition analysis (EDA) and it was shown that the covalent contribution is in the range 48–53% depending on the types of E atom and corresponding substituents.


2020 ◽  
Author(s):  
Yuezhi Mao ◽  
Matthias Loipersberger ◽  
Kareesa Kron ◽  
Jeffrey Derrick ◽  
Christopher Chang ◽  
...  

<p>To facilitate computational investigation of intermolecular interactions in the solution phase, we report the development of ALMO-EDA(solv), a scheme that allows the application of continuum solvent models within the framework of energy decomposition analysis (EDA) based on absolutely localized molecular orbitals (ALMOs). In this scheme, all the quantum mechanical states involved in the variational EDA procedure are computed with the presence of solvent environment so that solvation effects are incorporated in the evaluation of all its energy components. After validation on several model complexes, we employ ALMO-EDA(solv) to investigate substituent effects on two classes of complexes that are related to electrochemical CO<sub>2</sub> reduction catalysis. For [FeTPP(CO<sub>2</sub>−κC)]<sup>2−</sup> (TPP = tetraphenylporphyrin), we reveal that two ortho substituents which yield most favorable CO2 binding, −N(CH<sub>3</sub>)<sub>3</sub><sup>+</sup> (TMA) and −OH, stabilize the complex via through-structure and through-space mechanisms, respectively. The Coulombic interaction between the positively charged TMA group and activated CO<sub>2</sub> is found to be largely attenuated by the polar solvent. Furthermore, we also provide computational support for the design strategy of utilizing bulky, flexible ligands to stabilize activated CO<sub>2</sub> via long-range Coulomb interactions, which creates biomimetic solvent-inaccessible “pockets” in that electrostatics is unscreened. For the reactant and product complexes associated with the electron transfer from the <i>p</i>-terphenyl radical anion to CO<sub>2</sub> , we demonstrate that the double terminal substitution of <i>p</i>-terphenyl by electron-withdrawing groups considerably strengthens the binding in the product state while moderately weakens that in the reactant state, which are both dominated by the substituent tuning of the electrostatics component. These applications illustrate that this new extension of ALMO-EDA provides a valuable means to unravel the nature of intermolecular interactions and quantify their impacts on chemical reactivity in solution.<br></p>


RSC Advances ◽  
2015 ◽  
Vol 5 (93) ◽  
pp. 75895-75910 ◽  
Author(s):  
Milovan Stojanović ◽  
Marija Baranac-Stojanović

The effect of R/R′ and L on borenium ion affinities toward NH3, HCHO and Cl− has been evaluated by DFT calculations and rationalized on the basis of an energy decomposition analysis.


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