C20 Fullerene Research Articles

Interaction of a synthetic bio-relevant drug-molecule with C24 and B12N12 fullerene: A first-principles quantum chemical investigation

Interaction of a synthetic bio-relevant drug-molecule with C24 and B12N12 fullerene: A first-principles quantum chemical investigation

Pristine fullerene (C24) metals (Mo, Fe, Au) engineered nanostructured materials as an efficient electro-catalyst for hydrogen evolution reaction (HER): A density functional theory (DFT) study

The use of inexpensive, eco-friendly and earth-abundant transition metal-based carbon-based nanostructured materials for hydrogen evolution reaction (HER), has significantly increased. Hence, we examined the Mo-encapsulated, Fe-doped, and Au-decorated (AuFeMoC) dependent HER activity of C24 engineered nanostructured materials as an efficient electro-catalyst for HER using the density functional theory (DFT) approach at the PBE0/gen/6-311++G(d,p)/LanL2DZ level of theory. Our results revealed that AuFeMoC and FeMoC engineered surfaces show the strongest catalytic activity and are promising candidates for hydrogen production in Hydrogen evolution reaction (HER). Our calculations show that, after encapsulation, the Mo atom binds to the pristine C24 fullerene surface with a binding energy of −0.768 eV while stronger binding energy (−2.591 eV) is observed after doping the Mo-encapsulated fullerene (MoC) surface with Fe atom in the formation of engineered FeMoC. The calculated ΔGH values for H@AuFeMoC, H@FeMoC, H@MoC, and H@C is −0.0433, 0.1278, −0.0949, and −0.7920 eV, respectively. Based on the calculated ΔGH values, it is clear that H@AuFeMoC has the best catalytic activity of all engineered fullerene surfaces because it has ΔGH value closest to zero.

Design and computational study of the novel nano-buds of C20@C60 with high NLO properties

In this research, the possibility of forming nano-bud structures from the hybridization of C60 and C20 fullerenes was investigated using DFT calculation methods. The stability of the designed structures was ensured by the absence of imaginary frequency and cohesive energy calculations. The electrical properties of the designed molecules were studied by calculating the energy of the HOMO and LUMO orbitals. The lowest value of Eg obtained for structures A and B corresponds to the highest value of electric charge transfer from C60 to C20 calculated by NBO method. Strong absorption lines were observed in the visible region for the nanobud with structure B. It was also shown that the nonlinear optical properties of structures A and B were significantly improved compared to C60 and C20 and other designed compounds, which may be related to the amount of charge transfer and reduced Eg.

A charged diatomic triple-bonded U≡N species trapped in C82 fullerene cages

Actinide diatomic molecules are ideal models to study elusive actinide multiple bonds, but most of these diatomic molecules have so far only been studied in solid inert gas matrices. Herein, we report a charged U≡N diatomic species captured in fullerene cages and stabilized by the U-fullerene coordination interaction. Two diatomic clusterfullerenes, viz. UN@Cs(6)-C82 and UN@C2(5)-C82, were successfully synthesized and characterized. Crystallographic analysis reveals U-N bond lengths of 1.760(7) and 1.760(20) Å in UN@Cs(6)-C82 and UN@C2(5)-C82. Moreover, U≡N was found to be immobilized and coordinated to the fullerene cages at 100 K but it rotates inside the cage at 273 K. Quantum-chemical calculations show a (UN)2+@(C82)2− electronic structure with formal +5 oxidation state (f1) of U and unambiguously demonstrate the presence of a U≡N bond in the clusterfullerenes. This study constitutes an approach to stabilize fundamentally important actinide multiply bonded species.

Impact of innovative nanoadditives on biodigesters microbiome.

Nanoparticles (NPs) supplementation to biodigesters improves the digestibility of biowaste and the generation of biogas. This study investigates the impact of innovative nanoadditives on the microbiome of biodigesters. Fresh cow manure was anaerobically incubated in a water bath under mesophilic conditions for 30 days. Three different NPs (zinc ferrite, zinc ferrite with 10% carbon nanotubes and zinc ferrite with 10% C76 fullerene) were separately supplemented to the biodigesters at the beginning of the incubation period. Methane and hydrogen production were monitored daily. Manure samples were collected from the digesters at different time points and the microbial communities inside the biodigesters were investigated via real-time PCR and 16 S rRNA gene amplicon-sequencing. The results indicate that zinc ferrite NPs enhanced biogas production the most. The microbial community was significantly affected by NPs addition in terms of archaeal and bacterial 16 S rRNAgene copy numbers. The three ZF formulations NPs augmented the abundance of members within the hydrogenotrophic methanogenic phyla Methanobacteriaceae. While Methanomassiliicoccacaea were enriched in ZF/C76 supplemented biodigester due to a significant increase in hydrogen partial pressure, probably caused by the enrichment of Spirochaetaceae (genus Treponema). Overall, NPs supplementation significantly enriched acetate-producing members within Hungateiclostridiaceae in ZF/CNTs, Dysgonomonadaceae in ZF and Spirochaetaceae ZF/C76 biodigesters.

The extraordinary gravity of three atom 4π-components and 1,3-dienes to C20-nXn fullerenes; a new gate to the future of Nano technology

A quick glance to the adsorption, sensing, and energy storage abilities of C20 fullerene and its derivatives indicate that this small carbon cluster may have extraordinary properties which would make it a key part of the future of Nano actuators and Nano machines. For example, in the case of the gravity of three atom 4π-components (TACs) to these carbon cages, it should be noted that; the rate constants (K)s of the reaction of C20 fullerene with 1,3-butadiene (Diels-Alder (DA) process), and with 2-furan nitrile oxide ([3+2] cycloaddition (32CA process)) are 2.51(1011) M-1 s-1, and 1.4(107)M-1 s-1, respectively. However, the rate constant of the 32CAreaction between norbornadiene and 3,4-dihydro isoquinoline-N-oxide is about 2.56(10-5) M-1 s-1 (both by DFT and by experimental results). This simple comparison could show the extraordinary gravity of some TACs and dienes to C20 fullerenes.

Understanding electronic structures, chemical bonding, and fluxional behavior of Lu2@C2n (2n = 76-88) by a theoretical study.

Endohedral metal-metal-bonding fullerenes, in which encapsulated metals form covalent metal-metal bonds inside, are an emerging class of endohedral metallofullerenes. Herein, we reported quantum-chemical studies on the electronic structures, chemical bonding, and dynamic fluxionality behavior of endohedral metal-metal-bonding fullerenes Lu2@C2n (2n = 76-88). Multiple bonding analysis approaches, including molecular orbital analysis, the natural bond orbital analysis, electron localization function, adaptive natural density partitioning analysis, and quantum theory of atoms in molecules, have unambiguously revealed one two-center two-electron σ covalent bond between two Lu ions in fullerenes. Energy decomposition analysis with the natural orbitals for chemical valence method on the bonding nature between the encapsulated metal dimer and the fullerene cage suggested the existence of two covalent bonds between the metal dimer and fullerenes, giving rise to a covalent bonding nature between the metal dimer and fullerene cage and a formal charge model of [Lu2]2+@[C2n]2-. For Lu2@C76, the dynamic fluxionality behavior of the metal dimer Lu2 inside fullerene C76 has been revealed via locating the transition state with an energy barrier of 5 kcal/mol. Further energy decomposition analysis calculations indicate that the energy barrier is controlled by a series of terms, including the geometric deformation energy, electrostatic interaction, and orbital interactions.

A Density Functional Theory Study on Rechargeable Mg‐ion Batteries: C20 Fullerene as a Promising Anode Material

AbstractIn this study, the applicability of C20 fullerene as anode material in Mg‐ion batteries was investigated by Density Functional Theory (DFT). The interaction energy of the Mg2+ ion on C20 structure was found as −147.3 kcal/mol. The HOMO‐LUMO gap value decreased during Mg interaction on C20 structure while it increased during Mg2+ interaction. The charge distributions obtained after the interactions of Mg atoms on C20 show that charge transfer has taken place. The storage capacity value of C20 structure was calculated to be 893 mAhg−1. The diffusion barrier was calculated as 1.9 kcal/mol. In addition, the diffusion coefficient for Mg and Mg2+ on C20 structure were computed as 1.5×10−25 and 4.61×10−4, respectively. Consequently, the high storage capacity, high conductivity and low diffusion barrier for discharge/charge process and the suitability of the diffusion coefficient suggest that C20 fullerene structure can be used as a potential anode material in rechargeable Mg‐ion batteries.

A novel two-dimensional C36 fullerene network; an isotropic, auxetic semiconductor with low thermal conductivity and remarkable stiffness

The synthesis of two-dimensional (2D) C60 fullerene network (Nature (2022), 606, 507) with an anisotropic lattice is among the most exciting advances in the field of carbon-based materials, which has the potential to expand and establish a new class of 2D materials. In this work, a novel C36 fullerene 2D network with an isotropic structure is designed by screening of extensive and diverse fullerene lattices. Density functional theory calculations confirm that the herein predicted C36 fullerene network can exhibit an outstanding thermal stability up to 1500 K, an elastic modulus of 266 GPa, a negative Poisson's ratio of −0.05, and an indirect semiconducting electronic nature, with a HSE06(PBE) bad gap of 1.63 (0.97) eV. The phonon dispersion relation, mechanical and failure responses, and lattice thermal conductivity are explored with the aid of machine learning interatomic potentials (MLIPs). MLIP-based calculations close to the ground state confirm the dynamical stability, a negative Poisson's ratio of −0.06, an elastic modulus of 269 GPa, and a high tensile strength of around 26.8 GPa for the predicted 2D network. Room temperature phononic thermal conductivity and tensile strength are also predicted to be 9.8 ± 1 W/m.K and 15.9 GPa, respectively. This study introduces a novel isotropic and auxetic semiconducting full-carbon nanoporous nanosheet, with low thermal conductivity and appealing electronic, optical, and mechanical features, highlighting a bright prospect for the design and synthesis of novel fullerene-based 2D networks.

Design and computational evaluation of structural, electronic and optical properties of the oligomers of nC20 fullerene (n = 1–6)

In this research, linear and non-linear oligomers of fullerene C20 oligomers with different number of units were designed and their structural, electrical and optical properties were investigated. Cohesive energy which may be a reason for the stability of oligomers was calculated that the increase in cohesive energy was seen with increasing the number of fullerene units. Linear oligomers also have more cohesive energy than their nonlinear homologous. The tendency to form a ring was observed in nonlinear oligomers, which a complete ring with perfectly symmetrical structure was obtained in a 6-membered ring. HOMO-LUMO gap (Eg) values representing electrical conductivity were calculated and in the case of linear oligomers it increased with increasing number of C20 fullerene units. Analysis of partial electrical charges and MEP diagrams showed that the two ends of the oligomers have a negative charge and the junction of fullerene units has a positive partial charge. The polarizability, α, and the first hyperpolarizability, β, were calculated and an improvement in the non-linear optical (NLO) response was observed in the C20 oligomer, so that the α values for the linear pentamer oligomer and the β value for the Config-b-A tetramer were approximately 1300 and 18,000, respectively.

Performance of local G4(MP2) composite ab initio procedures for fullerene isomerization energies

Composite ab initio methods based on local coupled-cluster approaches calculate the CCSD(T)/CBS energy at a significantly reduced computational cost than the corresponding canonical methods. While showing promising performance for general thermochemistry, local composite ab initio methods have not been tested for fullerenes. Here we examine the performance of several local G4(MP2)-based methods for calculating the relative stability of a diverse set of C40 fullerenes. We use canonical G4(MP2) isomerization energies as reference data. Fullerenes provide a challenging problem for DLPNO-G4(MP2)-based methods. The DLPNO-based methods result in overall root-mean-square deviations (RMSDs) of 28.6 (NormalPNO with CCSD(T0)), 23.0 (NormalPNO with CCSD(T1)), and 16.1 (TightPNO with CCSD(T0)) kJ mol−1. The local natural orbital LNO-G4(MP2) method provides the best overall performance with an RMSD of 4.9 kJ mol−1. The DLPNO-G4(MP2) and LNO-G4(MP2) methods systematically overestimate the canonical G4(MP2) isomerization energies. Therefore, they provide valuable upper limits of the fullerene isomerization energies.

Evaluating the performance of ReaxFF potentials for sp2 carbon systems (graphene, carbon nanotubes, fullerenes) and a new ReaxFF potential.

We study the performance of eleven reactive force fields (ReaxFF), which can be used to study sp2 carbon systems. Among them a new hybrid ReaxFF is proposed combining two others and introducing two different types of C atoms. The advantages of that potential are discussed. We analyze the behavior of ReaxFFs with respect to 1) the structural and mechanical properties of graphene, its response to strain and phonon dispersion relation; 2) the energetics of (n, 0) and (n, n) carbon nanotubes (CNTs), their mechanical properties and response to strain up to fracture; 3) the energetics of the icosahedral C60 fullerene and the 40 C40 fullerene isomers. Seven of them provide not very realistic predictions for graphene, which made us focusing on the remaining, which provide reasonable results for 1) the structure, energy and phonon band structure of graphene, 2) the energetics of CNTs versus their diameter and 3) the energy of C60 and the trend of the energy of the C40 fullerene isomers versus their pentagon adjacencies, in accordance with density functional theory (DFT) calculations and/or experimental data. Moreover, the predicted fracture strain, ultimate tensile strength and strain values of CNTs are inside the range of experimental values, although overestimated with respect to DFT. However, they underestimate the Young’s modulus, overestimate the Poisson’s ratio of both graphene and CNTs and they display anomalous behavior of the stress - strain and Poisson’s ratio - strain curves, whose origin needs further investigation.

Investigation of fullerene motion on thermally activated gold substrates with different shapes

In the current study, the regime of motion of fullerene molecules on substrates with different shapes at a range of specific temperatures has been investigated. To do so, the potential energy of fullerene molecules was analyzed using the classical molecular dynamics method. C20, C36, C50, C60, C72, C76, C80, and C90 fullerene molecules were selected due to their spherical shapes with different sizes. In addition, to completely analyze the behavior of these molecules, different gold substrates, including flat, concave, the top side of the step (upward step), and the downside of the step (downward step) substrates, were considered. Specifying the regime of the motion at different temperatures is one of the main goals of this study. For this purpose, we have studied the translational and rotational motions of fullerene molecules independently. In the first step of the investigation, Lennard-Jones potential energy of fullerene molecules was calculated. Subsequently, the regime of motion of different fullerenes has been classified, based on their displacement and sliding velocity. Our findings indicated that C60 is appropriate in less than 5% of the conditions. However, C20, C76 and C80 molecules were found to be appropriate candidates in most cases in different conditions while they were incompetent only in seven situations. As far as a straight-line movement is considered, the concave geometry demonstrated a better performance compared to the other substrates. In addition, C72 indicated less favorable performance concerning the range of movement and diffusion coefficients. All in all, our investigation helps to understand the performance of different fullerene molecules on gold substrates and find their probable application, especially as a wheel in nano-machine structures.

Tungsten oxide/fullerene-based nanocomposites as electrocatalysts and parasitic reactions inhibitors for VO2+/VO2+ in mixed-acids

The relatively high cost of all-vanadium redox flow batteries (VRFBs) limits their widespread deployment. Enhancing the kinetics of the electrochemical reactions is needed to increase the power density and energy efficiency of the VRFB, and hence decrease the kWh cost of VRFBs. In this work, hydrothermally synthesized hydrated tungsten oxide (HWO) nanoparticles, C76, and C76/HWO were deposited on carbon cloth electrodes and tested as electrocatalysts for the VO2+/VO2+ redox reactions. Field Emission Scanning Electron Microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), high-resolution transmission electron microscope (HR-TEM,), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and contact angle measurements were used to characterize the electrodes’ material. The addition of the C76 fullerene to HWO was found to boost the electrode kinetics towards the VO2+/VO2+ redox reaction, by enhancing the conductivity and providing oxygenated functional groups at its surface. A composite of HWO/C76 (50 wt% C76) was found to be the optimum for the VO2+/VO2+ reaction, showing a ΔEp of 176 mV, compared to 365 mV in the case of untreated carbon cloth (UCC). Besides, HWO/C76 composites showed a significant inhibition effect for the parasitic chlorine evolution reaction due to the W-OH functional groups.

A quantum mechanical prediction of C24 fullerene as a DNA nucleobase biosensor

We aim to study the interaction of different nucleobases (adenine (A), thymine (T), guanine (G), cytosine (C) and uracil (U)) with the C24 fullerene (D6d symmetry) and to get the binding sequence of these nucleobases using dispersion (D3) corrected density functional theory (DFT). To evaluate the interaction between the nucleobases with the C24 fullerene, we have performed adsorption energy calculation, NBO analysis, Mulliken charge analysis, density of state calculation, sensing response analysis and recovery time calculation. We observed that adsorption sequence of nucleobase follows the trend as A > C > G > T > U. Due to interaction between the nucleobases and C24 fullerene charge redistribution takes place between them and induces the dipole moment. Adenine can be enisled from the other DNA nucleobase molecules, while cytosine and guanine can be sensed with the recovery time of 10−14 s in gas phase. The interaction energy increases for adenine and cytosine with solvent effect confirms their application as carrier.

Fullerenes Pose a Strain on Hybrid Density Functional Theory.

The computational modeling of fullerenes plays a fundamental role in designing low-dimension carbon nanostructures. Nevertheless, the relative energies of fullerenes larger than C20 and C24 have not been comprehensively examined by means of highly accurate ab initio methods, for example, the CCSD(T) method. Here we report such an investigation for a diverse set of 29 C40 isomers. We calculate the energies of the C40 fullerenes using the G4(MP2) composite ab initio method, which approximates the CCSD(T) energy in conjunction with a triple-ζ-quality basis set (CCSD(T)/TZ). The CCSD(T)/TZ isomerization energies span 43.1-763.3 kJ mol-1. We find a linear correlation (R2 = 0.96) between the CCSD(T)/TZ isomerization energies and the fullerene pentagon signatures (P1 index), which reflect the strain associated with fused pentagon-pentagon rings. Using the reference CCSD(T)/TZ isomerization energies, we examine the relationship between the percentage of exact Hartree-Fock (HF) exchange in hybrid density functional theory (DFT) methods and the pentagon-pentagon strain energies. We find that the performance of hybrid DFT methods deteriorates with the pentagon-pentagon strain energy. This deterioration in performance becomes more pronounced with the inclusion of high amounts of HF exchange. For example, for B3LYP (20% HF exchange), the root-mean-square deviation (RMSD) relative to G4(MP2) increases from 8.9 kJ mol-1 for the low-strain isomers (P1 = 11) to 18.0 kJ mol-1 for the high-strain isomers (P1 > 13). However, for BH&HLYP (50% HF exchange) the RMSD increases from 23.0 (P1 = 11) to 113.2 (P1 > 13) kJ mol-1. A similar trend is observed for the M06/M06-2X pair of functionals. Namely, for M06 (27% HF exchange) the RMSD increases from 0.8 (P1 = 11) to 21.0 (P1 > 13) kJ mol-1, whereas for M06-2X (54% HF exchange) the RMSD increases from 16.7 (P1 = 11) to 77.7 (P1 > 13) kJ mol-1. Overall, we find that the strain associated with pentagon adjacency is an inherently challenging problem for hybrid DFT methods involving high amounts of HF exchange and that there is an inverse relationship between the optimal percentage of HF exchange and the pentagon-pentagon strain energy. For example, for BLYP the optimal percentages of HF exchange are 13% (P1 = 11), 10% (P1 = 12), 7.5% (P1 = 13), and 6% (P1 > 13).

Theoretical investigation of the titanium—nitrogen heterofullerenes evolved from the smallest fullerene

In this survey, we are performed kinetic stability, global reactivity, atomic polar tensor (APT) charge and counter plots of Ti–N heterofullerenes developed from C20 fullerene with the molecular formula of C20-2nTinNn (n = 1–8), at B3PW91/6-311+G∗ level of theory. Also, we are investigated substituent effect of titanium and nitrogen heteroatoms on deuterium adsorption of the heterofullerenes according to density functional theory (DFT). Substituting of Ti–N units with various topology in the cap or equatorial position of heterofullerenes, changes significantly their electronic properties and causes different frontier molecular orbital energy separation (ΔEHOMO-LUMO). Hence, C18Ti1N1 and C10Ti5N5 are found as the best insulated species, while C12Ti4N4 and C4Ti8N8 are considered as the strongest conductive nanocage. Also, C14Ti3N3 cage shows the highest positive APT charge on Ti atom (+1.357, +1.053), while C12Ti4N4 cage shows the lowest positive APT charge on Ti atom (+0.031, −0.292). Accordingly, C14Ti3N3, and C12Ti4N4 exhibit the lowest, and the highest global electrophilicity; ω of 2.58, and 7.01 eV, respectively. As six D2 molecules are approached the C14Ti3N3 heterofullerene, its ΔEHOMO-LUMO (Eg) is increased from 1.29 eV in C14Ti3N3 heterofullerene to 2.11 eV in D2/C14Ti3N3 complex (∼+63.57%) indicating high sensitivity of it to adsorption of six D2 molecules through an exothermic process. As sixteen D2 molecules approaches the C4Ti8N8 nanocage, its Eg reduces from 0.97 to 0.73 eV (∼−24.74%) indicating high electrical conductivity of D2/C4Ti8N8 complex. Therefore, C4Ti8N8 as hopeful sensor, can be generate electrical signals when the D2 molecules approach.

(Invited) Fullerene and Fullerene Nanocomposites for an Enhanced All-Vanadium Redox Flow Battery

The dependence on fossil fuels to meet the world energy demand caused several social, economical, and environmental problems. An immediate switch to sustainable, clean, and renewable sources of energy is a necessity. To achieve this switch, developing efficient technologies to convert renewable energy sources into electricity is a necessity but not enough due to the intermittent behavior of renewable sources. The incorporation of energy storage systems as regulators allows for the sustainable integration of renewable energy resources into the electrical grid. Vanadium redox flow batteries (VRFBs) are the most promising candidates of the currently available energy storage technologies, as they have an unlimited capacity (theoretically) and design flexibility. Enhancing the kinetics of the VRFBs electrochemical reactions will enhance their energy efficiency, and hence decrease the kWh cost of VRFBs. Currently, carbon-based electrodes are employed due to their suitable stability and conductivity, but with no treatment, they suffer from sluggish kinetics, hydrophobicity, and parasitic reactions catalyzation.1 Modifying these carbon-based electrodes with carbon nanostructures2 and metal oxides(MOx)3 was found to enhance the kinetics at the VRFB electrodes.Even though fullerenes have very unique structural and chemical properties they were rarely explored for the VRFBs application.4 In this work, fullerene C76 showed superior electrocatalytic activity towards VO2+/VO2 + redox reaction in G1 and G3 VRFBs and eliminated the necessity for thermal treatment of the carbon cloth support while inhibiting the chlorine evolution in G3 VRFB. A composite of C76 and hydrated WOx that reduces the fullerene content to half further inhibited the chance for chlorine evolution while maintaining the catalytic activity.

Investigation of anti-tumor (E)-3-X-oxindole via functionalization of C20 nano structure: A DFT approach

In this work, cycloaddition of C20 fullerene with the selected oxindoles including (E)-3-X-oxindoles are investigated at the density functional theory (DFT). We have operated the gas phase (g), benzene (b) 1,2-dichloroethane (d), ethanol (e), nitromethane (n), dimethyl sulfoxide (d′) and H2O (w). The trend of dipole moment (µ) of products (Ia-IVa) also the trend of liquid phase-gas phase energy gap (ΔEl-g) seems proportional to the dielectric constant of solvent (ε). The stability of Ia-IVa seems proportional to ε and the H—bonding formation in different media. Unstable C20 similar to stable C60, with our scrutinized linear dienes can be carried out thermally exo cycloaddition at room temperature and currently hold responsible for the origin of synergistic and stereoselective, giving only one product.

Harnessing Greenhouse Gases Absorption by Doped Fullerenes with Externally Oriented Electric Field.

In this work, a theoretical investigation of the effects caused by the doping of C20 with silicon (Si) atom as well as the adsorption of CO, CO2 and N2 gases to C20 and C19Si fullerenes was carried out. In concordance with previous studies, it was found that the choice of the doping site can control the structural, electronic, and energetic characteristics of the C19Si system. The ability of C20 and C19Si to adsorb CO, CO2 and N2 gas molecules was evaluated. In order to modulate the process of adsorption of these chemical species to C19Si, an externally oriented electric field was included in the theoretical calculations. It was observed that C19Si is highly selective with respect to CO adsorption. Upon the increase of the electric field intensity the adsorption energy was magnified correspondingly and that the interaction between CO and C19Si changes in nature from a physical adsorption to a partial covalent character interaction.