scholarly journals Theoretical exploitation of donor-acceptor ability in low-valent group-14 elements complexes [E(PPh3 )2  → SiH2 ]2+ (E = C to Pb) using energy decomposition analysis

2019 ◽  
Vol 57 (4) ◽  
pp. 418-424
Author(s):  
Huynh Thi Phuong Loan ◽  
Hoang Van Duc ◽  
Duong Tuan Quang ◽  
Vo Thanh Cong ◽  
Pham Van Tat ◽  
...  
Keyword(s):  
Decomposition Analysis ◽  
Energy Decomposition Analysis ◽  
Energy Decomposition ◽  
Group 14 ◽  
Group 14 Elements ◽  
Donor Acceptor ◽  
Low Valent

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.

Bonding Situation in Dimeric Group 15 Complexes [(NHC)2(E2)] (E = N–Bi)

2014 ◽  
Vol 69 (7) ◽  
pp. 385-395 ◽  
Author(s):  
Nicole Holzmann ◽  
Gernot Frenking
Keyword(s):  
Density Functional ◽  
Decomposition Analysis ◽  
Borderline Case ◽  
Basis Sets ◽  
Energy Decomposition Analysis ◽  
Chemical Bonds ◽  
Energy Decomposition ◽  
Functional Theory ◽  
Donor Acceptor ◽  
Dinitrogen Complex

Quantum chemical calculations using density functional theory at the BP86 level in conjunction with triple-zeta polarized basis sets have been carried out for the title compounds. The nature of the bonding between the diatomic fragment and the NHC ligands is investigated with an energy decomposition analysis. The chemical bonds in the [(NHCMe)2(E2)] complexes can be discussed in terms of donor-acceptor interactions which consist of two NHCMe→E2←NHCMe donor components and two weaker components of the NHCMe←E2→NHCMe π backdonation. The out-of-phase (+)=(-) contribution of the s donation is always stronger than the in-phase (+)=(+) contribution. The electronic reference state of N2 in the dinitrogen complex [(NHCMe)2(N2)] is the highly excited 11Γg state which explains the anti-periplanar arrangement of the ligands. The gauche arrangement of the ligands in the heavier homologues [(NHCMe)2(E2)] (E = P-Bi) may be discussed using either the excited 11Γg state or the X1Σg+ ground state of E2 as reference states for the donor-acceptor bonds. The EDA-NOCV calculations suggest that the latter bonding model is better suited for the complexes where E = As-Bi while the phosphorus complex is a borderline case.

scholarly journals Direct estimate of the internal π-donation to the carbene centre within N-heterocyclic carbenes and related molecules

2015 ◽  
Vol 11 ◽  
pp. 2727-2736 ◽  
Author(s):  
Diego M Andrada ◽  
Nicole Holzmann ◽  
Thomas Hamadi ◽  
Gernot Frenking
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Decomposition Analysis ◽  
Heterocyclic Carbenes ◽  
Energy Decomposition Analysis ◽  
Energy Decomposition ◽  
Direct Estimate ◽  
Functional Theory ◽  
Bonding Analysis

Fifteen cyclic and acylic carbenes have been calculated with density functional theory at the BP86/def2-TZVPP level. The strength of the internal X→p(π) π-donation of heteroatoms and carbon which are bonded to the C(II) atom is estimated with the help of NBO calculations and with an energy decomposition analysis. The investigated molecules include N-heterocyclic carbenes (NHCs), the cyclic alkyl(amino)carbene (cAAC), mesoionic carbenes and ylide-stabilized carbenes. The bonding analysis suggests that the carbene centre in cAAC and in diamidocarbene have the weakest X→p(π) π-donation while mesoionic carbenes possess the strongest π-donation.

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