Fullerene C60 Research Articles

Solid state self‐assembly of an extended curved‐arm nickel(II) macrocycle with fullerene C60

Three new co‐crystalline structures are reported that contain fullerene C60 with the under‐represented Ni(II)‐dibenzotetraaza[14]annulene derivative, (5,14‐dihydro‐6,8,15,17‐tetrabenzyl‐2,3,11,12‐tetramethyldibenzo[b,i][1,4,8,11]tetraazacyclo‐tetradecine)nickel(II), [Ni(Bz4TMTAA)]. The single‐crystal X‐ray analysis shows that the three studied compounds crystallize in the monoclinic C2/c, Pnma orthorhombic and triclinic P space groups, with the two former compounds being polymorphs that are isostructural but differ in their symmetries. From the crystallographic results, a common packing arrangement is established, with C60 and [Ni(Bz4TMTAA)] molecules organised around one‐dimensional hollow channels, associated 1:1 and 1:2 complexation of the macrocycle and the fullerene molecules, the latter being organised into hexagonal arrays. Interestingly, one of the structures showed a skewed hexagonal channel arrangement with the introduction of water molecules. Hirshfeld surface analyses have been used to investigate non‐covalent interactions and cumulative π…π, C‐H…π, H…H, and N…C60 interactions between fullerene C60 and [Ni(Bz4TMTAA)] host molecule which are deemed the stabilizing factors for forming the sophisticated arrangements in the solid‐state. differences.

C60 fullerene improves the contractile activity of the injured rat muscle gastrocnemius

The powerful antioxidant properties of C60fullerenes have been widely used in biomedical nanotechnology. Owing to the negative effects of free radicals in oxidative stress processes, antioxidants are required to protect injured muscles. Here, the effect of water-soluble C60fullerenes (daily oral dose 1 mg kg-1) on the process of restoration of contractile activity of skeletal muscle of rats (muscle gastrocnemius) 15 d after the initiation of open trauma of different severity was studied for the first time. The structural organization of C60fullerene nanoparticles in aqueous solution was analyzed by dynamic light scattering and atomic force microscopy techniques. Such biomechanical parameters ofmuscle gastrocnemiuscontraction as integrated muscle power, levels of generation of its maximum and minimum force, and time interval until reaching 50% of the level of force response of the muscle were analyzed. Such biochemical indices as concentrations of c-reactive protein, creatinine, and lactate in the rat blood, as well as indices of pro- and antioxidant balance (activities of superoxide dismutase and catalase, the concentration of reduced glutathione) in the blood and muscle tissue of experimental animals, were investigated. It was found that application of water-soluble C60fullerenes statistically significantly improves biomechanical parameters of contraction of injuredmuscle gastrocnemiusat the level of 30-45 ± 3%, which is confirmed by normalization of biochemical indices in the blood and muscle tissue of rats at the level of 35-50 ± 3% and 20-37 ± 3%, correspondingly, relative to the open injury group. These findings open the possibility of using C60fullerenes as potential therapeutic nanoagents capable of correcting pathological states of the muscular system during the physiological repair of open injuries.

Global and Local Shielding/Deshielding Variation in C60 and C70 Fullerenes Upon Reduction: Evaluation of Aromaticity, 13C-NMR and Anisotropy Patterns.

Fullerenes are statically pleasant species featuring symmetric cages, which can be modified upon reduction. Here, we theoretically account for the variation of 13C-NMR patterns in C60 and C70 upon six-fold reduction and the overall variation of the enabled shielding/deshielding regions induced by π and σ electrons according to different orientations of the external field and the related anisotropy. Our results show a significant modification of the chemical shift given by the main variation of the σ33 (or δ33) shielding component under the principal axis system (PAS) of the chemical shift anisotropy (CSA) at the representative carbon nucleus. For C606- a shielding cone property is enabled from any orientation, accounting for a significant spherical aromatic character. In contrast, in C706‑, a shielding cone is reserved only for an axial-oriented field, with a deshielding cone behavior obtained from the complementary equatorial orientations. The overall anisotropy shows an inner isotropic region for C60 and C606-, with a continuous anisotropic outer contour for the latter. In contrast, C70 and C706- both show larger anisotropies, given the lesser spherical shape in addition to the modified π-surface. Such information is useful for further rationalizing the implementation of magnetic anisotropic molecular devices into fullerene-based materials.

Diels-Alder Cycloaddition of Cyclopentadiene to C60 and Si60 and Their Endohedral Li+ Counterparts.

Both silicon and carbon are elements located in group 14 on the periodic table. Despite some similarities between these two elements, differences in reactivity are important, and whereas carbon is a central element in all known forms of life, silicon is barely found in biological systems. Here, we investigate the Diels-Alder cycloaddition reaction of cyclopentadiene (CP) and cyclopentasildiene (CPSi) with fullerenes C60, Li+@C60, Si60, and Li+@Si60 using density functional theory methods. The results reveal distinct kinetic and thermodynamic trends that govern the reactivity and selectivity. For C60, the [6,6] pathway is kinetically and thermodynamically favored, whereas for Si60, the [5,6] pathway is preferred thermodynamically but not kinetically. The introduction of lithium cations increases the reactivity of both C60 and Si60. Energy decomposition analysis (EDA) unveils the importance of the components of the interaction energy between CPSi and the corresponding fullerenes. The findings provide insights into the interplay of electronic structure, substrate reactivity, and fullerene electrophilicity in cycloaddition reactions.

Metallofullerenol Gd@C82(OH)22 preserves human erythrocyte plasma membrane integrity from AAPH-induced oxidative stress: molecular mechanisms and antioxidant activity.

Metallofullerenols and fullerenols have attracted attention due to their remarkable ability to interact with various biologically relevant molecules, paving the way for biomedical applications, ranging from medical imaging techniques to drug carriers, acting with increased efficiency and reduced side effects. In this work, we investigated the effects of two fullerene derivatives, Gd@C82(OH)22 and C70(OH)12, on erythrocyte membrane components under oxidative stress conditions induced by 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) as a source of peroxyl radicals. The results demonstrated that gadolinium encapsulation within the fullerene cage enhanced the electron affinity of Gd@C82(OH)22, resulting in stronger antioxidant activity. Gd@C82(OH)22 formed a protective hydrophilic layer at the lipid-water interface, effectively preventing lipid peroxidation, oxidative protein damage, and potassium leakage, outperforming C70(OH)12. Both compounds improved membrane fluidity, but Gd@C82(OH)22 exhibited superior preservation of the erythrocyte lipid bilayer and protein function. Additionally, Gd@C82(OH)22 maintained the anion exchange function of Band 3 protein, which is critical for ionic homeostasis, by preventing oxidation-induced aggregation and preserving thiol groups. Despite its limited membrane penetration, Gd@C82(OH)22 stabilized membrane components through hydrogen bonding, which indirectly enhanced membrane stiffness and fluidity under oxidative stress. This external protection of membrane integrity reduced the risk of lipid peroxidation and oxidative damage to erythrocyte proteins. In contrast, C70(OH)12, while effective in protecting membrane lipids, was less effective in preserving protein structure. These findings highlight the unique protective properties of Gd@C82(OH)22, attributed to polarization effects induced by the encapsulated Gd atom. This study indicates that metallofullerenols, such as Gd@C82(OH)22, may have therapeutic potential in mitigating oxidative damage.

Non-classical sonochemical regioselective reaction of [4 + 2]-cycloaddition in the synthesis of morpholine adducts of C70 fullerene

In the reactions of amino alcohols (2-aminoethanol 1a, 2-(methylamino)ethanol 1b, amino-2-propanol 1c, 2-amino-1-phenylethanol 1d) with fullerene C70 were obtained the only 1,2-isomers of adducts of fullerene C70 with condensed morpholine fragments. Non-classical reactions [4 + 2]-cycloaddition take place in air in a toluene/DMF medium at room temperature under the influence of ultrasound. The reaction intermediate detected by EPR is the radical anion C70 –• (g = 2.0021 and ▵H = 2.6 G), obtained as a result of electron transfer from 2-aminoethanol 1a to the C70 framework.

A coarse-grained molecular dynamics simulation on the mechanical and thermal properties of natural rubber composites reinforced by fullerene nanoparticles.

The influence of fullerene C60 on the mechanical and thermal properties of natural rubber was systematically investigated using coarse-grained molecular dynamics simulations. The tensile results demonstrate that systems with longer NR chains exhibit reduced tensile strength. Moreover, the addition of C60 nanoparticles significantly enhanced the mechanical properties, with Young's modulus, yield strength, and tensile strength increasing by approximately 24.03%, 23.21%, and 51.61%, respectively, at a C60 concentration of 0.2 phr under a strain rate of 1e-6. Furthermore, the mechanical response was found to be strain rate-dependent, with higher strain rates leading to increased Young's modulus, yield strength, and tensile strength. Therefore, excessively high strain rates should be avoided in simulations to ensure consistency with real conditions. In terms of thermal properties, the addition of C60 nanoparticles was shown to significantly improve the thermal conductivity of natural rubber, with the optimal enhancement of 17.17% achieved at an inclusion level of approximately 0.1 phr. A comprehensive microstructural analysis, including mean square displacement, radial distribution function, coordination number, and interaction energy, revealed the reinforcement mechanisms of C60 on the mechanical and thermal properties of the nanocomposites. This study provides valuable insights into the rational design and fabrication of fullerene-reinforced natural rubber nanocomposites with superior mechanical and thermal performance. In this study, coarse-grained molecular dynamics simulations were performed using the LAMMPS software. The system used the real unit system with periodic boundary conditions. The interatomic interactions were described using the lj/expand model. The simulations were conducted at a temperature of 300K with a time step of 1fs.

Chlorination-Supported Shrinkage of C60 Fullerene to Non-classical C58 Cages.

We provide important novel insights into skeletal transformations of fullerene by reporting new cases of cage shrinkage in the most abundant C60 fullerene via a C2 loss. High-temperature (400-500 oC) chlorination of IPR C60 with SbCl5 or SbCl5/SbCl3 mixtures predominantly gives non-IPR C60Cln compounds via Stone-Wales rearrangements, but the present study further reveals non-classical C58Cln chlorofullerenes as by-products. The new C58(NC1)Cl20 and C58(NC1)Cl24 chlorides have been isolated by air-free HPLC and structurally characterized by X-ray crystallography. Their non-classical carbon cages feature one heptagon, two pairs of fused pentagons, one triple-pentagon junction, and one quartet of sequentially fused pentagons. However, the chlorination patterns and molecular shapes of C58(NC1)Cl20 and C58(NC1)Cl24 are essentially different. We propose the likely multistep transformation pathways toward the new compounds and further report the chlorination-promoted formation of chlorofullerenes with still smaller fullerene cages.

An Integral-Direct GOSTSHYP Algorithm for the Computation of High Pressure Effects on Molecular and Electronic Structure.

To simulate the effects of high pressure on molecular and electronic structure, methods based on the polarizable continuum model have emerged as a serious contender to the conventionally employed periodic boundary conditions. In this work, we present a highly efficient integral-direct algorithm for the Gaussians On Surface Tesserae Simulate HYdrostatic Pressure (GOSTSHYP) method. We examine the efficiency of this implementation on large chains of α-d-glucose units. Furthermore, we investigate the effects of high pressure on the binding energy of a supersystem consisting of a buckminster fullerene and a corannulene pincer system, and juxtapose various types of surfaces that constitute the boundary between the molecule and the implicit solvent. Our efficient implementation of the GOSTSHYP model paves the way for large-scale simulations of molecules under pressure.

Circularly polarized RABBITT on atomic shells with large orbital momentum

Abstract In light atoms, the technique of Reconstruction of Attosecond Bursts by Interference of Two-Photon Transitions (RABBITT), driven by circularly polarized radiation, enables a complete retrieval of ionization amplitudes in the XUV+IR regime, including their relative phases [Phys. Rev. Res. 6, L012002 (2024)]. In this work, we extend this method to heavier atoms by conducting numerical simulations of circularly polarized RABBITT on the Kr 3d and Xe 4d atomic shells. The XUV ionization dynamics in these atoms differ markedly due to the presence of a giant shape resonance in the 4d → Ef ionization channel of Xe, a feature absent in Kr. Nevertheless, when an IR photon is added to the XUV ionization, the results for Kr and Xe are surprisingly similar, with the ratio of absorption/emission matrix elements and their relative phases remaining close in value. Moreover, these ratios and phases show minimal variation even when the Xe atom is encapsulated within a C60 fullerene cage. In search for the Cooper-like minimum in the IR absorption amplitude ratios predicted in [J. Phys. B 57, 235601 (2024)], we extend our investigation to the Cr 4f shell where this minimum is indeed present.

The Balbiani body is formed by microtubule-controlled molecular condensation of Buc in early oogenesis.

Vertebrate oocyte polarity has been observed for two centuries and is essential for embryonic axis formation and germline specification, yet its underlying mechanisms remain unknown. In oocyte polarization, critical RNA-protein (RNP) granules delivered to the oocyte's vegetal pole are stored by the Balbiani body (Bb), a membraneless organelle conserved across species from insects to humans. However, the mechanisms of Bb formation are still unclear. Here, we elucidate mechanisms of Bb formation in zebrafish through developmental biomolecular condensation. Using super-resolution microscopy, live imaging, biochemical, and genetic analyses invivo, we demonstrate that Bb formation is driven by molecular condensation through phase separation of the essential intrinsically disordered protein Bucky ball (Buc). Live imaging, molecular analyses, and fluorescence recovery after photobleaching (FRAP) experiments invivo reveal Buc-dependent changes in the Bb condensate's dynamics and apparent material properties, transitioning from liquid-like condensates to a solid-like stable compartment. Furthermore, we identify a multistep regulation by microtubules that controls Bb condensation: first through dynein-mediated trafficking of early condensing Buc granules, then by scaffolding condensed granules, likely through molecular crowding, and finally by caging the mature Bb to prevent overgrowth and maintain shape. These regulatory steps ensure the formation of a single intact Bb, which is considered essential for oocyte polarization and embryonic development. Our work offers insight into the long-standing question of the origins of embryonic polarity in non-mammalian vertebrates, supports a paradigm of cellular control over molecular condensation by microtubules, and highlights biomolecular condensation as a key process in female reproduction.

Encapsulation effects on the structure and stability of O3, SO2, S2O, and S3 in C60, C70, and C80 fullerenes.

Encapsulation effects on the structure and stability of O3, SO2, S2O, and S3 in C60, C70, and C80 fullerenes.

All-carbon supramolecular complexation of a bilayer molecular nanographene with [60] and [70]fullerenes.

Supramolecular chemistry of carbon-based materials provides a variety of chemical structures with potential applications in materials science and biomedicine. Here, we explore the supramolecular complexation of fullerenes C60 and C70, highlighting the ability of molecular nanographene tweezers to capture these structures. The binding constant for the CNG-1⊃C70 complex was significantly higher than for CNG-1⊃C60, showing a clear selectivity for the more π-extended C70. DFT calculations confirmed these experimental results by showing that the interaction energy of C70 with CNG-1 is more than 5 kcal mol-1 higher than that of C60. Theoretical calculations predict that the dispersion interaction provides about 58-59% of the total interaction energy, followed by electrostatic attraction with 26% and orbital interactions, which contribute 15-16%. The racemic nanographene tweezers effectively recognize fullerene molecules and hold promise for future applications in chiral molecule recognition.

Sonochemical Isomerization of [5,6]-open Adducts of C60 Fullerene with Camphor Derivatives into [6,6]-closed Ones

: For the first time, a sonochemical method has been developed for the structural rearrangement of [5,6]-open mono- and poly adducts of fullerene C60 containing spirocyclic fragments of camphor analogs into [6,6]-closed isomers. The isomerization reaction occurs with quantitative yield under mild conditions: 1 hour at room temperature. A probable mechanism of sonochemical isomerization has been proposed. Mono- and poly adducts of C60 fullerene containing spirocyclic fragments of camphor analogues were obtained in the reaction of metal complex catalysis by the Pd(acac)2–2PPh3–4Et3Al system with the participation of fullerene and diazo compounds.

Enhancement of photoinduced reactive oxygen species generation in open-cage fullerenes.

Photodynamic therapy is an important tool in modern medicine due to its effectiveness, safety, and the ability to provide targeted treatment for a range of diseases. Photodynamic therapy utilizes photosensitizers to generate reactive oxygen species (ROS). Fullerenes can be used as photosensitizers to produce ROS in high quantum yields. Open-cage fullerenes are a subclass of fullerenes characterized by a partially open structure, with one or more openings or apertures. The promising electrochemical properties of open-cage fullerenes motivated us to investigate their use for DNA-cleavage and ROS generation under visible light irradiation through type I electron transfer and type II energy transfer reactions. Our results show that open-cage C60 fullerenes are more efficient for photoinduced cleavage of DNA and ROS generation via both the type I electron transfer and type II energy transfer pathways than pristine C60 or a C60 pyrrolidine derivative without open-cage. The greater efficiency of ROS generation by open-cage C60 fullerene in type I and type II reactions can be attributed to the increased rate of the initial intersystem crossing process, resulting from larger total reorganization energies, as indicated by computationally calculated relative rates using the Marcus equation, and the lower reduction potential of the open-cage derivative 3, as determined by CV, which facilitates a more efficient generation of the corresponding radical anion (C60˙-).

Understanding the effects of adduct functionalization on C60 nanocages for the hydrogen evolution reaction.

In this work, we use experimental and theoretical techniques to study the origin of the boosted hydrogen evolution reaction (HER) catalytic activity of two pyridyl-pyrrolidine functionalized C60 fullerenes. Notably, the mono-(pyridyl-pyrrolidine) penta-adduct of C60 has exhibited a remarkable HER catalytic activity as a metal-free catalyst, delivering an overpotential (η10) of 75 mV vs. RHE and a very low onset potential of -45 mV vs. RHE. This work addresses fundamental questions about how functionalization on C60 changes the electron density on fullerene cages for high-performance HER electrocatalysis.

Theoretical study on the mechanisms of formation of primal carbon clusters and nanoparticles in space.

We present a theoretical study of assembling clusters and nanoparticles in space from primordial aggregations of unbound carbon atoms. Geometry optimization and SCC-DFTB dynamics methods are employed to predict carbon clusters, their time evolution and stability. The initial density of the aggregates is found to be of primary importance for the structure of the clusters. Aggregates with low initial density yield clusters with an approximately equal prevalence of sp and sp2 hybridization with almost missing sp3. Higher initial density results in sp2-dominant molecules, resembling the carbon skeleton of polycyclic aromatic hydrocarbons (PAHs). Larger initial aggregations result in sp2-dominant polymers. Such materials are highly porous and possess a similarity to laterally bound nanotubes. Some clusters resemble fullerene building blocks. We employed metadynamics to model the inter-fragment coupling of such structures and predict the formation of spheroid nanoparticles, closely resembling fullerenes. One such structure has the lowest binding energy per atom among the studied molecules. All zero-dimensional forms, obtained by the simulations, conform to the experimentally detected types of molecules in space. The theoretical IR spectrum of the nanoparticles closely resembles that of fullerene C70 and therefore such imperfect structures may be mistaken for known fullerenes in experimental infrared (IR) telescope studies.

Topological Defects in Aggregation of the C60 Fullerene in the Isotactic Polypropylene Matrix

Basing on the data of small-angle neutron scattering for the nanocomposite composed of fullerene C60 (16.5 wt. %) in the matrix of isotactic polypropylene, we received information on clusterization of nanoparticles and defined their geometric parameters and dimensionality. In this paper, we propose interpretation of particle aggregation possessing the properties of surface fractal in the size range up to 80 nm observed using small-angle neutron scattering method. Basing on the well-known theories of defect structures of a fullerene molecule C60 in non-Euclidean metrics, in particular, of disclinations and monopole in two-dimensional spherical Gödel space—time, we formulate a lattice version for the action of monopole gas, in which with the lattice Monte Carlo method, using abelian projection, we estimate the energy of monopole currents at different monopole concentrations. In frames of the proposed model, it is possible to calculate fractal properties of the fullerene C60 in a polymer composite and also to interpret evolution of disclinations.

Effect of ethanol on the structure and aggregation properties of C₆₀ fullerenes

This study investigated the effect of ethanol on the structure and aggregation properties of C₆₀ fullerenes using an atomic force microscope. The fullerenes were dissolved in ethanol with different concentrations (0%, 10%, 25%, 50%, 100%) and deposited on silicon substrate for further analysis. The results showed that the size of molecular aggregates of fullerenes increased significantly with increasing ethanol concentration, starting from 15-20 nm in the absence of ethanol and reaching 80-100 nm at 100% ethanol. At the same time, the structure of the aggregates became more friable, indicating the solvent effect of ethanol. The interaction force measurements showed that the adhesion force of fullerenes to the substrate decreased with increasing ethanol concentration, indicating a weakening of adhesion and molecular interactions. These data confirm the significant effect of ethanol on the physicochemical properties of fullerenes and can be used to develop nanomaterials with variable structural characteristics.

Polarizability of exohedral lithium derivatives of fullerene C60

We have calculated mean polarizabilities of lithium–C60 exohedral derivatives and found that the depression of polarizability is typical for them as for covalent adducts of C60. This phenomenon implies the decreasing growth of the mean polarizability with the increasing number of the addends, attached to the fullerene core. Our previously developed model of the additive scheme, accounting this depression, works for lithium compounds only qualitatively, as the C60…Li contacts are non-covalent. Anisotropy of polarizability of C60Li n correlates with Li…Li distances in the molecules and almost independent of their symmetry.