Cleavage of carbon suboxide to give ketenylidene and carbyne ligands at a reactive tungsten site: a theoretical mechanistic study

RSC Advances ◽  
2016 ◽  
Vol 6 (5) ◽  
pp. 4014-4021 ◽  
Author(s):  
Liang Pu ◽  
Zhong Zhang ◽  
Qian-shu Li ◽  
R. Bruce King
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Mechanistic Study ◽  
Double Bonds ◽  
Functional Theory ◽  
Carbon Suboxide ◽  
Tungsten Complexes

The reaction of (MePPh2)4WCl2 with C3O2 results in stepwise cleavage of the two CC double bonds in C3O2 to give tungsten complexes containing phosphinoketenylidene and phosphinocarbyne ligands. The mechanism of this has been elucidated using density functional theory.

Theoretical elucidation of the energy conversion rate in organic photovoltaic cells of the fullerene nanostructure derivatives. A density functional theory study

2020 ◽  
Vol 19 (07) ◽  
pp. 2050025
Author(s):  
Nadjet Deddouche ◽  
Hafida Chemouri
Keyword(s):  
Density Functional Theory ◽  
Conversion Rate ◽  
Density Functional ◽  
Lithium Ion ◽  
Photovoltaic Cell ◽  
Energy Difference ◽  
Organic Photovoltaic ◽  
Mechanistic Study ◽  
Functional Theory ◽  
Kinetics Of

A comparative theoretical study of the kinetics of the Diels–Alder (DA) reaction between empty fullerene (C[Formula: see text]) and lithium ion encapsulated fullerene ([Formula: see text]) with 1,3 cyclohexadiene (C[Formula: see text]H[Formula: see text]) was carried out. This reaction takes place in a photovoltaic cell. The effect of the encapsulated [Formula: see text] ion on the conversion rate of solar energy into electricity has been highlighted through calculations based on the density functional theory (DFT). In addition, a static study using the global conceptual DFT indices, as part of the demonstration of the significant electrophilic power of the fullerene nanostructure, was carried out to show the effect of encapsulating the [Formula: see text] ion in this nanoparticle on the electrophilic power of Li[Formula: see text]@C[Formula: see text] and therefore on the acceleration of the reaction. The relationship between the HOMOdonor–LUMOacceptor energy difference and the DA reaction acceleration, and therefore the acceleration of light conversion (a rapid conversion implies a small gap), has been thoroughly examined. Moreover, a mechanistic study of the kinetics of the DA reaction of the fullerene involved in an organic photovoltaic cell has been carried out. In this section, a concerted synchronous mechanism with no effect of [Formula: see text] encapsulation on the synchronicity of the reaction was observed. Finally, it was revealed that Li[Formula: see text]@C[Formula: see text] reacted approximately 2466 times faster than C[Formula: see text]. Moreover, the experimental results were found in good agreement with the computer calculations.

Luminescence Mechanistic Study of BaLaGa3O7:Nd Using Density Functional Theory Calculations

2016 ◽  
Vol 55 (6) ◽  
pp. 2855-2863 ◽  
Author(s):  
Junling Meng ◽  
Xiaojuan Liu ◽  
Congting Sun ◽  
Chuangang Yao ◽  
Lifang Zhang ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Mechanistic Study ◽  
Functional Theory

Aromaticity in Heterocyclic and Inorganic Benzene Analogues

2008 ◽  
Vol 61 (3) ◽  
pp. 209 ◽  
Author(s):  
Simon C. A. H. Pierrefixe ◽  
F. Matthias Bickelhaupt
Keyword(s):  
Density Functional Theory ◽  
Molecular Orbital ◽  
Density Functional ◽  
Regular Structure ◽  
Model Systems ◽  
Bonding Mechanism ◽  
Double Bonds ◽  
Functional Theory ◽  
Ring Structures ◽  
Inorganic Benzene

Recently, we presented a molecular orbital (MO) model of aromaticity that explains, in terms of simple orbital-overlap arguments, why benzene (C6H6) has a regular structure with delocalized double bonds. Here, we show that the same model and the same type of orbital-overlap arguments also account for heterocyclic and inorganic benzene analogues, such as s-triazine (C3N3H3), hexazine (N6), borazine (B3N3H6), boroxine (B3O3H3), hexasilabenzene (Si6H6), and hexaphosphabenzene (P6). Our MO model is based on accurate Kohn–Sham density-functional theory (DFT) analyses of the bonding in the seven model systems, and how the bonding mechanism is affected if these molecules undergo geometrical deformations between regular, delocalized ring structures and distorted ones with localized double bonds. It turns out that also in the heterocyclic and inorganic benzene analogues, the propensity of the π electrons is always to localize the double bonds, against the delocalizing force of the σ electrons. The latter in general prevails, yielding the regular, delocalized ring structures. Interestingly, we find one exception to this rule: N6.

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