scholarly journals The influence of the grafted aryl groups on the solvation properties of the graphyne and graphdiyne - a MD study

2019 ◽  
Vol 17 (1) ◽  
pp. 703-710 ◽  
Author(s):  
Avni Berisha

AbstractThe mechanism of the adsorption and grafting of diazonium cations onto the surface of graphyne and graphdiyne was investigated using Density Functional Theory (DFT). The adsorption energy (both in vacuum and water as solvent) of the phenyl diazonium cation was evaluated at three different positions of the graphyne and graphdiyne surface. Moreover, the lowest energy adsorption sites were used to calculate and plot Non-covalent Interactions (NCI). The Bond Dissociation Energy (BDE) results (up to 66 kcal/mol) for the scission of the phenyl group support the remarkable stability of the grafted layer. As both of these materials are non-dispersible in aqueous solution, in this work through the use of Molecular Mechanics (MM) and Molecular Dynamics (MD) we explored also the effect of the grafted substituted aryl groups derived from aryldiazonium salts onto the solvation properties of these materials.

Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1281
Author(s):  
Zikri Altun ◽  
Erdi Ata Bleda ◽  
Carl Trindle

An atom trapped in a crystal vacancy, a metal cage, or a fullerene might have many immediate neighbors. Then, the familiar concept of valency or even coordination number seems inadequate to describe the environment of that atom. This difficulty in terminology is illustrated here by four systems: H atoms in tetragonal-pyramidal rhodium cages, H atom in an octahedral cobalt cage, H atom in a MgO octahedral hole, and metal atoms in C20 fullerenes. Density functional theory defines structure and energetics for the systems. Interactions of the atom with its container are characterized by the quantum theory of atoms in molecules (QTAIM) and the theory of non-covalent interactions (NCI). We establish that H atoms in H2Rh13(CO)243− trianion cannot be considered pentavalent, H atom in HCo6(CO)151− anion cannot be considered hexavalent, and H atom in MgO cannot be considered hexavalent. Instead, one should consider the H atom to be set in an environmental field defined by its 5, 6, and 6 neighbors; with interactions described by QTAIM. This point is further illustrated by the electronic structures and QTAIM parameters of M@C20, M=Ca to Zn. The analysis describes the systematic deformation and restoration of the symmetric fullerene in that series.


2015 ◽  
Vol 13 (1) ◽  
Author(s):  
Ernesto Chigo Anota ◽  
Gregorio Hernández Cocoletzi ◽  
Andres Manuel Garay Tapia

AbstractAb-initio calculations using density functional theory (DFT) are used to investigate the non-covalent interactions between single wall armchair boron nitride nanotubes (BNNTs) with open ends and several heterocyclic molecules: thiophene (T; C


2021 ◽  
Author(s):  
Michelle Enst ◽  
Ganna Gryn'ova

<div> <div> <div> <p>Metal-organic frameworks offer a convenient means for capturing, transporting, and releasing small molecules. Rational design of such systems requires an in-depth understanding of the underlying non-covalent interactions, and the ability to easily and rapidly pre-screen candidate architectures in silico. In this work, we devised a recipe for computing the strength and analysing the nature of the host-guest interactions in MOFs. Using experimentally characterised complexes of calcium-adipate framework with 4,4’-bipyridine and 1,2-bis(4-pyridyl)ethane guests as test systems, we have assessed a range of density functional theory methods, energy decomposition schemes, and non-covalent interactions indicators across realistic periodic and finite supramolecular cluster scales. We find that appropriately constructed clusters readily reproduce the key interactions occurring in periodic models at a fraction of the computational cost and with an added benefit of diverse density partitioning schemes. Host-guest interaction energies can be reliably computed with dispersion- corrected density functional theory methods; however, decoding their precise nature demands insights from energy decomposition schemes and quantum-chemical tools beyond local bonding indices (e.g., the quantum theory of atoms in molecules), such as the non-covalent interactions index and the density overlap regions indicator. </p> </div> </div> </div>


Sign in / Sign up

Export Citation Format

Share Document