A DFT study of the electronic and magnetic properties of C36Si24 fullerenes

Bernal-Texca, Francisco; Anota, E. Chigo; Carrillo, Lorenzo Tepech; Castro, Miguel

doi:10.1016/j.comptc.2017.01.013

Cited by 18 publications

(7 citation statements)

References 38 publications

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“…The Δ E * is used as a direct indicator of kinetic stability. A large Δ E * implies high kinetic stability and low chemical reactivity as it is energetically unfavorable to add electrons to a high‐lying LUMO or to extract electrons from a low‐lying HOMO . Combination of alkyl substituted N‐methyl pyrrolidinium cation (P yr 1R , R = C 1 to C 6 ) with four anions, BF 4 − , PF 6 − , TFSI − , and TFO − has been investigated in this work.…”

Section: Introductionmentioning

confidence: 99%

Electronic structural studies of pyrrolidinium‐based ionic liquids for electrochemical application

Sivaji

Vijayalakshmi

George

2019

Int J of Quantum Chemistry

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Electrochemical stability and noncovalent interactions escorting the cyclic ammonium-based ionic liquids composed of N-alkyl-substituted N-methyl pyrrolidinium (P yr 1R) (R = methyl, ethyl, propyl, butyl, pentyl, hexyl) cations and four anions hexafluorophosphate (PF 6 ), tetrafluoroborate (BF 4 ), bis(trifluoromethylsulfonylimide (TFSI), and trifluoromethane sulfonate (TFO) have been analyzed using the density functional theory. Electronic structures, electrochemical window, frontier orbital energy difference (HOMO-LUMO gap), binding energies, vibrational spectra of these ion pairs were characterized. It has been established that ion pair formation is largely reigned by C HÁ Á ÁF interactions between anionic fluorine for BF 4 − and PF 6 − anions and C HÁ Á ÁO interactions between anionic oxygen for TFSI and TFO anions and pyrrolidinic proton, methyl, or alkyl group protons of the cations. The effect of alkyl chain length and pairing anions of the alkyl substituted N-methyl pyrrolidinium-based ionic liquids on the electrochemical window was investigated. The results revealed that the HOMO energy of pairing anions is the key factor to decide the electrochemical window. Further quantification of noncovalent interactions in terms of electrostatic and hydrogen bonding interactions has been brought out employing a novel method with the aid of Mulliken and Merz-Singh-Kollman charges, prevailed in pyrrolidinium-based ionic liquids. K E Y W O R D S density functional theory, electrochemical stability, HOMO-LUMO, hydrogen bonding, ionic liquid 1 | INTRODUCTION Room temperature (RT) ionic liquids (ILs) have gained considerable attention due to their unique properties such as low vapor pressure, high ionicconductivity, and wide electrochemical window and are promising candidates as electrolytes for electrochemical applications. [1,2] ILs has many energy applications such as battery technologies, [3][4][5][6][7] fuel cells, [8,9] dye sensitized solar cells, [10] thermo-electrochemical cells, [11] super capacitors, [12] actuators, [13] etc. Since the physicochemical and electrochemical properties of ILs depend on the structure of their constituent cations and anions, it is possible to tune these properties by choosing various combinations of anions and cations; this drawn the attention of researchers to design new materials for many different fields. Hence, ILs are recognized as designer solvents. [14] The synthesis and systematic thermophysical and electrochemical investigations by Neale and coworkers [15] on ethereal functionalized cyclic alkyl ammonium-based ILs established that these ILs are electrochemically more stable and are suitable for electrochemical devices such as battery systems, fuel cells, or super capacitors.

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Section: Introductionmentioning

confidence: 99%

Electronic structural studies of pyrrolidinium‐based ionic liquids for electrochemical application

Sivaji

Vijayalakshmi

George

2019

Int J of Quantum Chemistry

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“…As model systems of fullerenes, we include the generic C 60 , in addition to the equivalent Si 24 C 36 , and B 24 N 36 analogs. The main hypothesis to follow to improve the interaction between nanosheets and fullerenes is to consider in the nanostructures the combination of heteronuclear and homonuclear bonds. , Moreover, nonstoichiometric fullerenes are found to be more stable than their stoichiometric counterparts . The fullerene adsorption was carried out on a large finite graphene nanosheet (C 130 H 28 ), where the dangling bonds at the edges were saturated with hydrogen atoms.…”

Section: Computational Methodologymentioning

confidence: 99%

Chemical and Physical Viewpoints About the Bonding in Fullerene–Graphene Hybrid Materials: Interaction on Pristine and Fe-Doped Graphene

et al. 2019

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A DFT scheme was adopted to study the noncovalent/covalent attachment of fullerenes (C60, Si24C36, and B24N36) to graphene and Fe-doped graphene nanosheets (FeG). Geometrical, energetic, and electronic properties related to the physical and chemical nature of the bonding were characterized. The results show that fullerenes are physisorbed on graphene with adsorption energies of 0.7–1.2 eV, while the chemisorption is reached on FeG by cycloadditions with adsorption energies of 1.6–4.4 eV and is depending on the topology of FeG. The origin of the stability was analyzed from chemical and physical viewpoints, applying methods such as atom-in-molecules (AIM), natural bond orbital (NBO), and energy decomposition analysis based on absolutely localized molecular orbitals (ALMO-EDA). It is shown that noncovalent graphene–fullerene hybrids are assembled by van der Waals interactions but are also governed by permanent electrostatic Coulombic interactions that contribute at least 31% to the binding stability and depending on the bond polarity of fullerenes. Otherwise, the cycloaddition of fullerenes with FeG is reached by the formation of highly polarized chemical bonds, which were described in a detailed orbital picture. The structural stability of the covalent complexes is dominated by the contribution of charge transfer and permanent electrostatic physical effects. Additionally, the polarizability is an intrinsic property of fullerenes that also determines its binding strength on graphene (up to 35%); in this way, the larger polarizability of fullerenes increases the interaction stability. Therefore, this work gives insights into the bonding properties governing the stability of hybrid materials formed by self-assembly of fullerenes onto emerging low-dimensional nanostructures.

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“…Finally, in synthetic chemistry, the binary arrangements of atoms in heteroatom-doped fullerenes are important for stability and chemical reactivity. For example, boron-doped fullerenes have applications ranging from photonics to hydrogen storage, [24][25][26] nitrogen-doped fullerenes have suggested applications in fuel cells 27 , and silicon-doped fullerenes in catalysis 28 .…”

Section: Introductionmentioning

confidence: 99%