Theoretical studies on structure, formation and nature of bond in a Disila-, Digerma- and distannacyclobutene ring

2016 ◽  
Vol 15 (04) ◽  
pp. 1650032 ◽  
Author(s):  
Mehdi Bayat ◽  
Fatemeh Amraie ◽  
Sadegh Salehzadeh
Keyword(s):  
Structure Formation ◽  
Theoretical Study ◽  
Decomposition Analysis ◽  
Energy Decomposition Analysis ◽  
Energy Decomposition ◽  
Group 14 ◽  
Group 14 Elements ◽  
Covalent Contribution ◽  
Formation Energies ◽  
Wiberg Bond Indices

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.

Ab initio and DFT studies on the structures, binding energies and nature of bonds in X2Y3 metal clusters (X+ = Li+, Na+ and K+; ${\rm Y}_{3}^{2-} = {\rm Zn}_{3}^{2-}, {\rm Cd}_{3}^{2-}$ and ${\rm Hg}_{3}^{2-}$)

2015 ◽  
Vol 14 (06) ◽  
pp. 1550043 ◽  
Author(s):  
Masoud Hatami ◽  
Mehdi Bayat ◽  
Hassan Keypour ◽  
Sadegh Salehzadeh
Keyword(s):  
Ab Initio ◽  
Electrostatic Interactions ◽  
Density Functional ◽  
Theoretical Study ◽  
Population Analysis ◽  
Binding Energies ◽  
Energy Decomposition ◽  
Zinc Cadmium ◽  
Covalent Contribution ◽  
Wiberg Bond Indices

A comprehensive theoretical study on the structure and stability of linear and triangular isomers of anionic clusters of zinc, cadmium and mercury [Formula: see text] and their binding with one and two alkali metal cations ( X + = Li +, Na +, K +) has been investigated at the density functional (BP86 and B3LYP) and ab initio (MP2, MP4 and coupled cluster single and double (CCSD)) methods. The results showed that in all cases, the triangular geometry with D3h symmetry is more stable than linear one. The calculated values of interaction energies (IE) between [Formula: see text] anions and two X+ cations, Wiberg bond indices (WBI) and the electron densities at bond critical points (BCP), ρ(BCP), for Y–X bonds show that among all complexes investigated here at all levels of theory Zn 3 Li 2 and Hg 3 K 2 have the largest and the smallest values of IE, WBI and ρ(BCP), respectively. The natural charges of the atoms and WBI involved in the bonding as well as the global value of the charge transfer ΔQ from [Formula: see text] to X+ cation in X2Y3 clusters, evaluated through natural population analysis, confirmed that covalent contribution in Y–X bond formation increases from K + to Li +. Also the energy decomposition analyses (EDA) were used to detect the nature of interaction in the complexes. The results confirmed that the contribution of electrostatic interactions in present complexes is almost more than 70%.

Hetero-Diels–Alder reactions involving Fe(CO)3-coordinated dienal and formyltrimethylenemethane catalyzed by Lewis acids — A theoretical study

2009 ◽  
Vol 87 (7) ◽  
pp. 1074-1080 ◽  
Author(s):  
Carles Acosta-Silva ◽  
Òscar González-Blanco ◽  
Vicenç Branchadell
Keyword(s):  
Lewis Acids ◽  
Density Functional ◽  
Theoretical Study ◽  
Decomposition Analysis ◽  
Diels Alder ◽  
The Other ◽  
Energy Decomposition Analysis ◽  
Energy Decomposition ◽  
Trans Conformer ◽  
The One

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.

scholarly journals Through-Bond and Through-Space Interactions in [2,2]Cyclophanes

2021 ◽  
Author(s):  
Sérgio Galembeck ◽  
Renato Orenha ◽  
Rafael Madeira ◽  
Letícia Peixoto ◽  
Renato Parreira
Keyword(s):  
Electron Density ◽  
Noncovalent Interactions ◽  
Topological Analysis ◽  
Decomposition Analysis ◽  
Energy Decomposition Analysis ◽  
Relative Importance ◽  
Energy Decomposition ◽  
Covalent Contribution ◽  
Pauli Repulsion ◽  
Open Question

The interpretation of the distortions of the electron distribution in [2,2]cyclophanes (22-CPs) is controversial. Some studies indicate that there is an accumulation of electron density (ρ) outside the cavity of 22-CPs. The nature of through-space (ts) interaction is still under debate. The relative importance of ts and through-bond (tb) is an open question. In an attempt to clarify these points, we have investigated five 22-CPs and their corresponding toluene dimers by molecular orbitals analysis, electron density difference analysis, some topological analysis of ρ (quantum theory of atoms in molecules (QTAIM), electron localization function (ELF) and noncovalent interactions (NCI)), and energy decomposition analysis with natural orbitals for chemical valence (EDA-NOCV). ρ is concentrated inside the inter-ring region. All the analyses indicated that ts is predominant. The ts is composed by attractive dispersion and Pauli repulsion, with a small covalent contribution. Except for 1 and 6, all the compounds present inter-ring bond paths.

scholarly journals A theoretical study on borenium ion affinities toward ammonia, formaldehyde and chloride anions

RSC Advances ◽  
2015 ◽  
Vol 5 (93) ◽  
pp. 75895-75910 ◽  
Author(s):  
Milovan Stojanović ◽  
Marija Baranac-Stojanović
Keyword(s):  
Dft Calculations ◽  
Theoretical Study ◽  
Decomposition Analysis ◽  
Energy Decomposition Analysis ◽  
Energy Decomposition

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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