Fullerene C60 Research Articles

Mechanism for Site-Selective Hydroboration of C70 Fullerene with Borane by DFT-D3 Study.

We studied the hydroboration of the C70 fullerene using both B3LYP-D3(BJ)/6-311G(d,p) and M06-2X-D3/6-311G(d,p) levels of theory, incorporating the empirical dispersion interaction, and Fukui index calculations. Potential energy surfaces (PESs) and Gibbs free energy surfaces (GFESs) were calculated for the pathways from four BH3 adducts (located at the AB, CC, D, and E sites) on the C70 to eight products formed by the 1,2-addition of BH3 across the four [6,6]-ring fused bonds (AB, CC, DE, and EE) and across the two [5,6]-ring fused bonds (AA and DD). These pathways are two-step consecutive reactions. We denoted the positions on the fullerene cage as A through E, from the pole to the equator, based on the D5h symmetry of the C70 fullerene. In the first step reaction, the product ratios for the four adduct intermediates should be as the primary intermediate BH3(D), the secondary intermediate BH3(AB), the tertiary intermediate BH3(CC), and the minor intermediate BH3(E), based on the Fukui indices. In addition, in the second step reaction, transition states (TSs) from four adduct intermediates to eight product isomers, namely, BH2(A)H (B) to BH2(E)H (E), were obtained using the QST2 method. The calculated reaction coordinates showed exothermic reactions for all bonds except the EE bond. We also confirmed the transition states by frequency calculations and intrinsic reaction coordinate (IRC) analyses. The PESs and GFESs suggest spontaneous processes for the four isomers, of which the primary products are BH2(A)H (B) and its isomer BH2(B)H (A), the secondary product is BH2(C)H (C), and the tertiary product is BH2(D)H (D), all formed through adduct intermediates. Therefore, through the hydroboration reaction of C70, we could predict and design the site selectivity of C70 by controlling the energy barrier of the transition state in the second step of the reaction. This implies that we could selectively synthesize mainly BH2(B)H (A) isomers across the AB-[6,6]-ring fused bond and also design BH2(D)H(D) isomers across the DD-[5,6]-ring fused bond. Also, the calculations of formation rate constants can well simulate the experimental ratio of two C70H2 isomers by the hydrolysis of BH2(A)H(B), BH2(B)H(A), and BH2(C)H(C) products at room temperature.

Reducing Interfacial Recombination in Inverted Perovskite Solar Cells With Selenophene-Substituted PCBM: Comparison With Thiophene and Furan Substitution.

Reducing the interfacial recombination and improving the charge transfer capability of charge transport layers are effective strategies to enhance the efficiency and stability of perovskite solar cells (PSCs). This study evaluates, for the first time, the effects of selenophene substitution in the chemical structure of phenyl-butyric acid methyl ester (PCBM) on the performance and stability of inverted PSCs. Selenophene substitution was compared to thiophene and furan substitutions, and the reference PCBM without chalcogenophene moiety. Additionally, this study investigates the differences between using the fullerene cages C70 and C60 in the PCBM chemical structure. The photovoltaic results demonstrate that, with an adequate control of the thickness of the electron transport layer (ETL), incorporating the selenophene moiety in the structures of fullerenes enhances the photovoltaic parameters of PSCs. This improvement results from the reduction in trap-assisted recombination, an increase in electron mobility, and the improved charge extraction processes. The use of C70, as opposed to C60, allows for the preparation of a series of ETLs with comparable thicknesses, although slightly lower efficiencies. This feature facilitates a systematic comparative analysis focused on variations in the electron properties of ETLs, thereby avoiding the inclusion of issues related to thickness and charge recombination processes.

Formation of coatings from accelerated ions of fluorinated fullerene C<sub>60</sub>(CF<sub>3</sub>)<sub>12</sub>

The first results of the deposition of coatings from accelerated ions of fluorinated fullerene C60(CF3)12 are presented. The coatings were formed at room temperature on Si substrates from a beam of singly charged C60(CF3)+12 ions with an energy of 5 keV, as well as from an ion beam, which also contained doubly charged C60(CF3)122+ ions and a certain amount of ionized fragments of molecules. The properties and structure of coatings obtained from accelerated ions of fluorinated fullerene are compared with the properties and structure of coatings obtained from accelerated C60 fullerene ions under the same conditions. According to X-ray photoelectron spectroscopy, fluorinated fullerene coatings contain about 4% fluorine. Investigations of the coatings structure and chemical bonds by X-ray photoelectron spectroscopy and Raman scattering showed that the presence of fluorine leads to decrease in the content of sp3 bonds and the formation of graphite-like sp2 structures. Coating hardness (H) and Young's modulus (E) compared to C60 ion coatings decrease from 36 to 18 GPa and from 245 to 133 GPa, respectively. The H/E ratio remained the same (~0.14). Tribological tests have shown for all coatings a friction coefficient close to 0.1. Also, all coatings are characterized by very low wear, less than 10–7 mm3/N∙m for coatings obtained from C60(CF3)12 ions, the contact angle is ~76°–78°. In the absence of fluorine, for the coating obtained from C60 ions, it is ~90°.

Important structural parameter for curvature effect of TM-N4 embeded C70 fullerenes as electrocatalysts for CO2 reduction interpreted with machine learning and first-principles calculations

In this work, TM-N4 sites embedded on curved C70 Fullerenes (TMN4(n)@C64, n = 1–5 which denote the doping positions and TM = Sc-Zn) were designed as efficient catalysts for electrochemical CO2 reduction reaction (ECO2RR). With interpretable machine learning (ML) and first-principles calculations, the performance of TM-N4 sites as possible electrocatalysts for ECO2RR under the curvature effect were revealed. After the screen procedure of catalyst stability, CO2 activation and selectivity of 50 designed systems, VN4(3), CrN4(3), MnN4(2), FeN4(2, 3, 5)@C64 were identified as high performance catalysts for ECO2RR to CH4, with limiting potential of -0.41 V, -0.26 V, -0.28 V, -0.35 V, -0.25 V and -0.17 V respectively, outperform the TM-N4 catalysts on the flat surface. A key structural descriptor K which can reflect the curvature effect of TM-N4 sites on the curved surface was identified with ML models. The gradient boosting regression (GBR) and sure independence screening and sparsifying operator (SISSO) algorithm reveal that the structural parameter K have strong association with the CO2 adsorption and significant influence on the selectivity of catalysts. Interestingly, the structural parameter K can influence more the binding of O-bonded intermediates than C-bonded intermediates. With the GBR algorithm, an effective model for the prediction of the limiting potential for C1 products were obtained. This study clarified the curvature effect of TM-N4 supported on the curved surface, and provides valuable guidance for the designing of TM-N4 single atom catalysts for ECO2RR on curved surface.

Xerogel synthesis from carbon materials and glue inspired by Japanese-solid-calligraphy ink

Abstract Japanese-solid-calligraphy ink is a xerogel made by mixing soot and glue followed by molding and drying. Herein, we prepare xerogels from glue and 1 or 2 carbon materials (fullerene C60, multiwalled and single-walled carbon nanotubes, nanodiamonds, graphite, graphene, and carbon nanohorns) and characterize their surface morphology, indentation hardness, surface resistivity, and other physical properties. Our ecofriendly and simple synthesis does not require special equipment and affords xerogels holding promise as electrode materials.

Design of N-doped C60-σ-B-doped C60 photodetector based on resonant tunneling diode using DFT and NEGF method.

Photodetectors utilizing donor/acceptor (D/A) molecules have the capacity to detect light through molecular interactions between a donor and an acceptor molecule. These devices leverage electronic or optical changes within molecules when exposed to light, resulting in observable modifications. The unique properties of photodetectors with D/A molecules make them valuable tools in various fields, including molecular electronics. This paper presents the modeling and simulation of a single-molecule photodetector based on a D/A molecule configuration. The acceptor molecule used is N-doped C60 fullerene, while the donor molecule is B-doped C60 fullerene. Initially, simulations were conducted at zero bias voltage to determine the energy and states of the bipartite molecule. Subsequently, the system's Hamiltonian was computed based on these results. The self-consistent field method (SCF) and optical self-energy coefficients were employed for modeling. Finally, the current-voltage curve of the device was derived for various input light frequencies. The simulation and modeling results demonstrated that the device exhibited negative differential resistances at bias voltages of 0.33 V, 1.58 V, and - 0.93 V, depending on the input light frequency. Furthermore, the designed device demonstrated the ability to detect and absorb waves with different frequencies. The number of current peaks in the current-voltage curve varied with by altering the number of optical modes. The computational work was conducted using the software package of Atomistix ToolKit (ATK-2018.06) and MATLAB code. The calculations were based on the density functional theory (DFT) approach and the self-consistent field method, specifically the non-equilibrium Green function (NEGF). The exchange correlation function was investigated using the generalized gradient approximation (GGA) proposed by Perdew, Burke, and Ernzerhof (PBE). For the calculations, we employed the double-ζ plus polarization (DZP) basis set. Initially, the structures of N doped-C60-σ-B-doped-C60 molecule underwent optimization using the DFT approach implemented in the ATK package. This optimization process allowed us to extract the parameters of the molecule. Subsequently, we utilized the NEGF formalism in MATLAB software to model and simulate photodetector based on the optimized molecule. We calculated important features of the photodetector, such as photocurrent, and compared the performance of the photodetector using photons with energies of 2 and 3 eV.

Surprising Dynamics Phenomena in the Diels-Alder Reaction of C60 Uncovered with AI.

We performed an extensive artificial intelligence-accelerated quasi-classical molecular dynamics investigation of the time-resolved mechanism of the Diels-Alder reaction of fullerene C60 with 2,3-dimethyl-1,3-butadiene. In a substantial fraction (10%) of reactive trajectories, the larger C60 noncovalently attracts the 2,3-dimethyl-1,3-butadiene long before the barrier so that the diene undergoes the series of complex motions including roaming, somersaults, twisting, and twisting somersaults around the fullerene until it aligns itself to pass over the barrier. These complicated processes could be easily missed in typically performed quantum chemical simulations with shorter and fewer trajectories. After the barrier is passed, the bonds take longer to form compared to the simplest prototypical Diels-Alder reaction of ethene with 1,3-butadiene despite high similarities in transition states and barrier widths evaluated with intrinsic reaction coordinate (IRC) calculations. C60 is mainly responsible for these differences as its reaction with 1,3-butadiene is similar to the reaction with 2,3-dimethyl-1,3-butadiene: the only substantial difference being that the extra methyl groups double the probability of the prolonged alignment phase in dynamics. These additional calculations of C60 with 1,3-butadiene could be performed via active learning more easily by reusing the data generated for the other two reactions, showing the potential for larger-scale exploration of the effects of different substrates in the same types of reactions.

Docetaxel-tethered di-Carboxylic Acid Derivatised Fullerenes: A Promising Drug Delivery Approach for Breast Cancer.

Docetaxel (DTX) has become widely accepted as a first-line treatment for metastatic breast cancer; however, the frequent development of resistance provides challenges in treating the disease.C60 fullerene introduces a unique molecular form of carbon, exhibiting attractive chemical and physical properties. Our study aimed to develop dicarboxylic acid-derivatized C60 fullerenes as a novel DTX delivery carrier. This study investigated the potential of water-soluble fullerenes to deliver the anti-cancer drug DTX through a hydrophilic linker. The synthesis was carried out using the Prato reaction. The spectroscopic analysis confirmed the successful conjugation of DTX molecules over fullerenes. The particle size of nanoconjugate was reported to be 122.13 ± 1.63nm with a conjugation efficiency of 76.7 ± 0.14%. The designed conjugate offers pH-dependent release with significantly less plasma pH, ensuring maximum release at the target site. In-vitro cell viability studies demonstrated the enhanced cytotoxic nature of the developed nanoconjugate compared to DTX. These synthesized nanoscaffolds were highly compatible with erythrocytes, indicating the safer intravenous route administration. Pharmacokinetic studies confirmed the higher bioavailability (~ 6 times) and decreased drug clearance from the system vis-à-vis plain drug. The histological studies reveal that nanoconjugate-treated tumour cells exhibit similar morphology to normal cells. Therefore, it was concluded that this developed formulation would be a valuable option for clinical use.

Theoretical Insight into Complexation Between Cyclocarbons and C60 Fullerene.

This work conducts a comprehensive theoretical study on the non-covalent complexation between cyclocarbons and C60 fullerene for the first time. The binding energy between cyclocarbons and C60 fullerene is significantly stronger than that between two C18 or two C60 fullerenes, indicating a particularly strong affinity. The cyclocarbons and C60 fullerene can spontaneously assemble into complexes in the gas phase at room temperature, and the hydrophobic effect caused by the solvent environment can promote this binding. The binding strength with C60 fullerene increases almost linearly with the increase of cyclocarbon size, and the C34@C60 dimer exhibits a perfect nano-Saturn structure. As the ring size increases, the angle between the two cyclocarbons of the 2 : 1 trimers formed by cyclocarbons and C60 fullerene gradually decreases. In C60@2 C34 trimer, the fullerene is symmetrically surrounded by two cyclocarbons. The results on the trimers formed by cyclocarbon and C60 fullerenes in a 1 : 2 ratio showed when the cyclocarbon sandwiched between two fullerenes is not quite large, the trimers exhibit an ideal dumbbell-like structure, and the presence of the first fullerene has a significant synergistic effect on the binding of the second one. The cyclocarbon greatly promotes the dimerization of fullerenes, which acted as a "molecular glue".

A rapid compression large-volume press with a high pressure jump above 10GPa within milliseconds.

A high pressure jump through a rapid compression within milliseconds (ms) provides an important approach for searching novel matters and investigating their physical and chemical properties. Herein, we report a unique rapid-compression large volume press with a high pressure jump above 10GPa within 20ms by introducing a Walker-type module and hydraulic accumulators. The sample pressure can be rapidly increased from 1-5GPa to 12-16GPa by different modest compression rates varying from 10-2 to 633.5 GPa/s. The rapid pressure jump on the specimen has been successfully verified through the observed rapid phase transition of ZnTe from semiconductor to metal transitions, as evidenced by the variation in its electrical conductivity. The highest pressure jump of 10.2GPa within a rise time of 16.1ms is achieved, which is significantly higher than previous results (5.8GPa within 20ms) using a Bridgman-type anvils in such an apparatus. We found that rapid compression significantly enhances the phase transformation of C70 fullerene from a disordered graphite to an amorphous phase compared to static high-pressure experiments. The high pressure jump technique developed in this study will thus have great applications in materials science, physics, chemistry, and earth science.

A Quantum Mechanical MP2 Study of the Electronic Effect of Nonplanarity on the Carbon Pyramidalization of Fullerene C60.

Among C60's diverse functionalities, its potential application in CO2 sequestration has gained increasing interest. However, the processes involved are sensitive to the molecule's electronic structure, aspects of which remain debated and require greater precision. To address this, we performed structural optimization of fullerene C60 using the QM MP2/6-31G* method. The nonplanarity of the optimized icosahedron is characterized by two types of dihedral angles: 138° and 143°. The 120 dihedrals of 138° occur between two hexagons intersecting at C-C bonds of 1.42 Å, while the 60 dihedrals of 143° are observed between hexagons and pentagons at C-C bonds of 1.47 Å. NBO analysis reveals less pyramidal sp1.78 hybridization for carbons at the 1.42 Å bonds and more pyramidal sp2.13 hybridization for the 1.47 Å bonds. Electrostatic potential charges range from -0.04 a.u. to 0.04 a.u. on the carbon atoms. Second-order perturbation analysis indicates that delocalization interactions in the C-C bonds of 1.42 Å (143.70 kcal/mol) and 1.47 Å (34.98 kcal/mol) are 22% and 38% higher, respectively, than those in benzene. MP2/Def2SVP calculations yield a correlation energy of 13.49 kcal/mol per electron for C60, slightly higher than the 11.68 kcal/mol for benzene. However, the results from HOMO-LUMO calculations should be interpreted with caution. This study may assist in the rational design of fullerene C60 derivatives for CO2 reduction systems.

C60–bicyclo[2.2.1]heptanes: new hybrid mono- and hexakis-adducts of the C60 fullerene

New fullerene derivatives keep attracting attention of chemists due to their possible applications. Fullerene adducts with saturated polycyclic hydrocarbons represent one of the promising classes of fullerene compounds but still have rare examples. To enhance molecular diversity of fullerene derivatives in this direction, we have synthesized the representatives of C60–bicyclo[2.2.1]heptanes. For this purpose, we first produced the unsubstituted organic hydrazones from various bicyclo[2.2.1]heptane derivatives and then used the organic precursors in the reactions with C60. New homofullerenes and methanofullerenes with one bicyclo[2.2.1]heptane fragment have been obtained under metal-complex catalysis conditions at the fullerene C60:hydrazone molar ratio equal to 1:1.5. If fullerene C60:hydrazone ratio was 1:10, homofullerenes with six bicyclo[2.2.1]heptane fragments were synthesized, which can be isomerized into methanofullerenes when boiling in o-dichlorobenzene.

A Negatively Curved Nanographene with Four Embedded Heptagons.

Negatively curved nanographenes are considered as cutouts of three-dimensional fully sp2-hybridized carbon allotropes such as Schwarzites. Here we present the synthesis of a C76 cut-out of the Schwarzite 8-4-1-p proposed by Lenosky et al. and investigate its optical as well as electrochemical properties. Furthermore, supramolecular interactions with fullerenes C60 and C70 were studied.

Interaction of fullerenes C60 with pristine and substituted buckybowls: a theoretical study

Non-covalent interactions between experimentally available buckybowls (coronene, corannulene, sumanene, triazasumanene, pentachlorocorannulene, decachlorocorannulene) and fullerenes C60 were systematically studied by using several theoretical methods. Peculiarities of these interactions were determined using electrostatic potential maps, independent gradient model, and symmetry adapted perturbation theory (SAPT0). SAPT0 calculations confirmed that dispersion (contribute 63-70% in attraction) and electrostatic interactions (23-28%) play the major role for C60 binding, whereas induction forces contribute to Eint only moderately (5-7%) for all structures studied herein. Cl-substituted corannulenes were calculated to be the most favorable structures for C60 binding. Ab initio molecular dynamics (AIMD) simulations confirmed stability of the studied complexes at different temperatures. Our investigations established the high potential of the studied buckybowls for usage in molecular tweezers.

Investigation of phytotoxic effects of fullerene С60 with the use of Allium-test

Aim. To investigate the cytogenetic effects of water-soluble fullerene C60 with the use of Allium test. To study the influence of various concentrations of fullerene С60 on the morpho-physiological parameters of A. cepa. Methods. The influence of different concentrations of fullerene С60 (25–100 μg/ml) on the induction of root formation and their growth, as well as its cytogenetic effects on the meristematic cells of root apices, were investigated. Results. It was found that fullerene C60 at concentrations of 50 and 75 μg/ml induced root formation and stimulated root growth, though causing minor deformations. Also, it was shown that fullerene С60 disrupts the progression of various phases of mitosis in the meristematic cells of roots, along with the occurrence of chromosomal aberrations at all investigated concentrations. Conclusions. The cytogenetic effects of water-soluble fullerene C60 were investigated for the first time using the Allium-test. Both positive effects on the morphophysiological parameters of A. cepa and its genotoxicity were demonstrated, which could indicate the disruptions in the mechanisms of spindle formation.

AI-assisted models to predict chemotherapy drugs modified with C60 fullerene derivatives.

Employing quantitative structure-activity relationship (QSAR)/ quantitative structure-property relationship (QSPR) models, this study explores the application of fullerene derivatives as nanocarriers for breast cancer chemotherapy drugs. Isolated drugs and two drug-fullerene complexes (i.e., drug-pristine C60 fullerene and drug-carboxyfullerene C60-COOH) were investigated with the protein CXCR7 as the molecular docking target. The research involved over 30 drugs and employed Pearson's hard-soft acid-base theory and common QSAR/QSPR descriptors to build predictive models for the docking scores. Energetic descriptors were computed using quantum chemistry at the density functional-based tight binding DFTB3 level. The results indicate that drug-fullerene complexes interact more with CXCR7 than isolated drugs. Specific binding sites were identified, with varying locations for each drug complex. Predictive models, developed using multiple linear regression and IBM Watson artificial intelligence (AI), achieved mean absolute percentage errors below 12%, driven by AI-identified key variables. The predictive models included mainly quantitative descriptors collected from datasets as well as computed ones. In addition, a water-soluble fullerene was used to compare results obtained by DFTB3 with a conventional density functional theory approach. These findings promise to enhance breast cancer chemotherapy by leveraging fullerene-based drug nanocarriers.

Fullerene C60 Decreases Inflammation, Oxidative Stress and Apoptosis Induced by 7,12-Dimethylbenz[a]Anthracene (DMBA) in Muscle Tissue Via Caspase-3 and NRF-2 Protein Signaling Pathway

Fullerene C60 Decreases Inflammation, Oxidative Stress and Apoptosis Induced by 7,12-Dimethylbenz[a]Anthracene (DMBA) in Muscle Tissue Via Caspase-3 and NRF-2 Protein Signaling Pathway

Self-propelled directed transport of C60 fullerene on the surface of the cone-shaped carbon nanotubes

Directed transportation of materials at molecular scale is important due to its crucial role in the development of nanoelectromechanical devices, particularly the directional movements along the carbon nanotubes (CNTs), due to the applications of CNTs as nano-manipulators, confined reactors, and drug or other materials delivery systems. In the present investigation, we evaluate the movements of C60 fullerenes on the surface of the cone-shaped CNTs. The fullerene molecules indicate directed motion toward the narrower end of CNTs, which is due to the potential energy gradient along the nanotube length. A continuum model is proposed to evaluate the mechanism of the directed motion and the results of the theoretical model are compared with numerical simulations. Directed movements have been examined at various opening angles of CNTs, considering the trajectories of motions, variation of potential energy, and diffusion coefficients. At smaller opening angles, the driving force on the C60 increases and the molecule experiences more directed transport along the nanotube. The motion of fullerene has also been simulated inside the cone-shaped CNTs, with similar opening angle, and different average radius. At lower average radius of the cone-like nanotubes, the motion of C60 is comparatively more rectilinear. Directional transport of fullerene has been observed in the opposite direction, when the molecule moves on the external surface of the cone-like CNTs, which is due to the stronger interaction of C60 with the parts of the external surface with larger radius. The effect of temperature has been evaluated by performing the simulations at the temperature range of 100 to 400 K. The direction of the velocity reveals that the thermal fluctuations at higher temperatures hinder the directed motion of molecule along the cone-shaped CNTs. The results of the present study propose a new method to obtain directed transport of molecules which can be helpful in different applications such as drug delivery systems.

Controlled Synthesis of C70 Fullerene Micro/Nanotubes

The physical features of the synthesis and further growth of C70 fullerene micro/nanotubes in the volume of an evaporating drop on a substrate surface have been studied. The morphological and optical characteristics of one dimensional C70 nanostructures have been determined. The possibility of controlling the geometric dimensions of the synthesized C70 tubes by changing both the concentration of C70 in the initial drop and the temperature of the substrate used was demonstrated experimentally.

Fullerene and fullerene whisker are not carcinogenic to the lungs and pleura in rat long-term study after 2-week intra-tracheal intrapulmonary administration

Fullerene whiskers (FLW)s are thin rod-like structures composed of C60 and C70 fullerene (FL). The shape of FLWs suggests potential toxic effects including carcinogenicity to the lung and pleura, similar to effects elicited by asbestos and multi-walled carbon nanotubes (MWCNT)s. However, no long-term carcinogenic studies of FL or FLW have been conducted. In the present study we investigated the pulmonary and pleural carcinogenicity of FL and FLW. Twelve-week-old male F344 rats were administered 0.25 or 0.5 mg FL, FLW, MWCNT-7, and MWCNT-N by intra-tracheal intra-pulmonary spraying (TIPS). Acute lung lesions and carcinogenicity were analyzed at 1 and 104 weeks after 8 doses/15 days TIPS administration. At week 1, FLW, MWCNT-7, and MWCNT-N significantly increased alveolar macrophage infiltration. Expression of Ccl2 and Ccl3, reactive oxygen species production, and cell proliferation were significantly increased by administration of MWCNT-7 and MWCNT-N but not FL or FLW. At week 104, the incidence of bronchiolo-alveolar adenoma plus adenocarcinoma was significantly increased in the MWCNT-7 and MWCNT-N groups, and the incidence of mesothelioma was significantly increased in the MWCNT-7 group. No significant induction of pulmonary or pleural tumorigenesis was observed in the FL or FLW groups. The number of 8-OHdG-positive cells in the alveolar epithelium was significantly increased in the MWCNT-7 and MWCNT-N groups but not in the FL or FLW groups. FL and FLW did not exert pulmonary or pleural carcinogenicity in our study. In addition, oxidative DNA damage was implicated in MWCNT-induced lung carcinogenesis, suggesting that it may be a useful initial marker of carcinogenicity.