Synthesis of indano[60]fullerene thioketone and its application in organic solar cells.

Evaporable indano[60]fullerene ketone (FIDO) was converted to indano[60]fullerene thioketone (FIDS) in high yield by using Lawesson's reagent. Three compounds with different substituents in para position were successfully converted to the corresponding thioketones, showing that the reaction tolerates compounds with electron-donating and electron-withdrawing substituents. Computational studies with density functional theory revealed the unique vibrations of the thioketone group in FIDS. The molecular structure of FIDS was confirmed by single-crystal X-ray analysis. Bulk heterojunction organic solar cells using three evaporable fullerene derivatives (FIDO, FIDS, C60) as electron-acceptors were compared, and the open-circuit voltage with FIDS was 0.16 V higher than that with C60.

Hypoglycemic and hypolipidemic effect of pentaamino acid fullerene C60 derivative in rats with metabolic disorder.

Pentaamino acid fullerene C60 derivative is a promising nanomaterial, which exhibited antihyperglycemic activity in high-fat diet and streptozotocin-induced diabetic rats. This study investigates the effect of pentaaminoacid C60 derivative (PFD) in rats with metabolic disorders. Rats were assigned to 3 groups (of 10 rats each) as follows: Group 1 (normal control), group 2 included the protamine-sulfate-treated rats (the untreated group of animals with the model metabolic disorder); group 3 (Protamine sulfate + PFD) included the protamine-sulfate-treated model rats that received an intraperitoneal injection of PFD. Metabolic disorder in rats was initiated by protamine sulfate (PS) administration. The PS + PFD group was injected intraperitoneally with PFD solution (3 mg/kg). Protamine sulfate induces biochemical changes (hyperglycemia, hypercholesterolemia, and hypertriglyceridemia) in the blood and morphological lesions in rat liver and pancreas. The potassium salt of fullerenylpenta-N-dihydroxytyrosine in protamine sulfate-induced rats normalized blood glucose level and the serum lipid profile and improved hepatic function markers. Treatment with PFD restored pancreas islets and liver structure of protamine sulfate-induced rats compared to the untreated group. PFD is a promising compound for further study as a drug against metabolic disorders.

CH3 CN@open-C60 : An Effective Inner-Space Modification and Isotope Effect Inside a Nano-Sized Flask.

Despite several small molecules being encapsulated inside cage-opened fullerene derivatives, such species have not considerably affected the structures and properties of the outer carbon cages. Herein, we achieved an effective inner-space modification for an open-cage C60 derivative by insertion of a neutral CH3 CN molecule into the cavity. The CH3 CN@open-C60 thus obtained showed an enhanced polarity, thus affording an easy separation from a mixture containing the empty cage by column chromatography on silica gel, without the preparative HPLC that was needed for previous cases. The less negative reduction potentials with respect to those of empty cage reflect the decreased energy level of the LUMO, which is supported by the DFT calculations. NMR spectroscopy, single-crystal X-ray analysis, and theoretical calculations revealed that both the presence of the encapsulated CH3 CN and cage deformation caused by the CH3 CN play an essential role in the change of the electronic properties. Furthermore, the favored binding affinity of deuterated acetonitrile CD3 CN with internal C60 surface is discussed.

Electrostatic effects on water-soluble fullerene derivatives interaction with cytochrome c and cytochrome c oxidase.

Water-soluble fullerene derivatives are good candidates for various biological applications such as anticancer or antimicrobial therapy, cytoprotection, enzyme inhibition, and many others. Their toxicity, both in tissue culture and in vivo, is a critical characteristic for the development and restriction of these applications. The effects of six water-soluble cationic and anionic polysubstituted fullerene derivatives on cytochrome c oxidase activity in rat brain mitochondria and the possibility of cytochrome c binding were studied. We found that the ability of these fullerene derivatives to bind with cytochrome c oxidase and charged molecules like eosin Y strongly depends on their electrostatic charge. As was shown, the cationic fullerene derivative inhibits cytochrome c oxidase that has the overall negative electrostatic potential completely, unlike anionic derivatives. Thus, it confirms the essential role of electrostatic interactions in the interaction of fullerene derivatives with the active site of enzymes. The results explore how cationic fullerene derivatives play a role in mitochondrial dysfunction, oxidative stress, and cytotoxicity.

Cheminformatics and Machine Learning Approaches to Assess Aquatic Toxicity Profiles of Fullerene Derivatives.

Fullerene derivatives (FDs) are widely used in nanomaterials production, the pharmaceutical industry and biomedicine. In the present study, we focused on the potential toxic effects of FDs on the aquatic environment. First, we analyzed the binding affinity of 169 FDs to 10 human proteins (1D6U, 1E3K, 1GOS, 1GS4, 1H82, 1OG5, 1UOM, 2F9Q, 2J0D, 3ERT) obtained from the Protein Data Bank (PDB) and showing high similarity to proteins from aquatic species. Then, the binding activity of 169 FDs to the enzyme acetylcholinesterase (AChE)-as a known target of toxins in fathead minnows and Daphnia magna, causing the inhibition of AChE-was analyzed. Finally, the structural aquatic toxicity alerts obtained from ToxAlert were used to confirm the possible mechanism of action. Machine learning and cheminformatics tools were used to analyze the data. Counter-propagation artificial neural network (CPANN) models were used to determine key binding properties of FDs to proteins associated with aquatic toxicity. Predicting the binding affinity of unknown FDs using quantitative structure-activity relationship (QSAR) models eliminates the need for complex and time-consuming calculations. The results of the study show which structural features of FDs have the greatest impact on aquatic organisms and help prioritize FDs and make manufacturing decisions.

Enhanced Photocatalytic Coupling of Benzylamine to N-Benzylidene Benzylamine over the Organic-Inorganic Composites F70-TiO2 Based on Fullerenes Derivatives and TiO2.

The organic-inorganic composites F70-TiO2, based on fullerene with carboxyl group derivatives and TiO2 semiconductor, have been designed and constructed to become an optical-functional photocatalyst via the facile sol-gel method. The composite photocatalyst obtained shows excellent photocatalytic activity for the high-efficiency conversion of benzylamine (BA) to N-benzylidene benzylamine (NBBA) with air pressure at a normal temperature under visible light irradiation. By optimizing the composition, the composites with the 1:15 mass ratio of F70 and TiO2, denoted as F70-TiO2(1:15), demonstrated the highest reaction efficiency for benzylamine (>98% conversion) to N-benzylidene benzylamine (>93% selectivity) in this study. However, pure TiO2 and fullerene derivatives (F70) exhibit decreased conversion (56.3% and 89.7%, respectively) and selectivity (83.8% and 86.0%, respectively). The UV-vis diffuse reflectance spectra (DRS) and Mott-Schottky experiment's results indicate that the introduction of fullerene derivatives into anatase TiO2 would greatly broaden the visible light response range and adjust the energy band positions of the composites, enhancing the sunlight utilization and promoting the photogenerated charge (e--h+) separation and transfer. Specifically, a series of results on the in situ EPR tests and the photo-electrophysical experiment indicate that the separated charges from the hybrid could effectively activate benzylamine and O2 to accelerate the formation of active intermediates, and then couple with free BA molecules to form the desired production of N-BBA. The effective combination, on a molecular scale, between fullerene and titanium dioxide has provided a profound understanding of the photocatalysis mechanism. This work elaborates and makes clear the relationship between the structure and the performance of functional photocatalysts.

An H2 O2 Molecule Stabilized inside Open-Cage C60 Derivatives by a Hydroxy Stopper.

An H2 O2 molecule was isolated inside hydroxylated open-cage fullerene derivatives by mixing an H2 O2 solution with a precursor molecule followed by reduction of one of carbonyl groups on its orifice. Depending on the reduction site, two structural isomers for H2 O2 @open-fullerenes were obtained. A high encapsulation ratio of 81 % was attained at low temperature. The structures of the peroxosolvate complexes thus obtained were studied by 1 H NMR spectroscopy, X-ray analysis, and DFT calculations, showing strong hydrogen bonding between the encapsulated H2 O2 and the hydroxy group located at the center of the orifice. This OH group was found to act as a kinetic stopper, and the formation of the hydrogen bonding caused thermodynamic stabilization of the H2 O2 molecule, both of which prevent its escape from the cage. One of the peroxosolvates was isolated by HPLC, affording H2 O2 @open-fullerene with 100 % encapsulation ratio, likely due to the intramolecular hydrogen-bonding interaction.

Self-Organization of Fullerene Derivatives in Solutions and Biological Cells Studied by Pulsed Field Gradient NMR.

Fullerene derivatives are of great interest in various fields of science and technology. Fullerene derivatives are known to have pronounced anticancer and antiviral activity. They have antibacterial properties. Their properties are largely determined by association processes. Understanding the nature and properties of associates in solvents of various types will make it possible to make significant progress in understanding the mechanisms of aggregation of molecules of fullerene derivatives in solutions. Thus, this work, aimed at studying the size and stability of associates, is relevant and promising for further research. The NMR method in a pulsed field gradient was used, which makes it possible to directly study the translational mobility of molecules. The sizes of individual molecules and associates were calculated based on the Stokes-Einstein model. The lifetime of associates was also estimated. The interaction of water-soluble C60 fullerene derivatives with erythrocytes was also evaluated. The values of self-diffusion coefficients and the lifetime of molecules of their compounds in cell membranes are obtained. It is concluded that the molecules of fullerene derivatives are fixed on the cell surface, and their forward movement is controlled by lateral diffusion.

Fullerene Derivatives (CN-[OH]ß) and Single-Walled Carbon Nanotubes Modelled as Transporters for Doxorubicin Drug in Cancer Therapy.

Carbon nanomaterials have received increasing attention in drug-delivery applications because of their distinct properties and structures, including large surface areas, high conductivity, low solubility in aqueous media, unique chemical functionalities, and stability at the nano-scale size. Particularly, they have been used as nano-carriers and mediators for anticancer drugs such as Cisplatin, Camptothecin, and Doxorubicin. Cancer has become the most challenging disease because it requires sophisticated therapy, and it is classified as one of the top killers according to the World Health Organization records. The aim of the current work is to study and investigate the mechanism of combination between single-walled carbon nanotubes (SWCNTs) and fullerene derivatives (CN-[OH]ß) as mediators, and anticancer agents for photodynamic therapy directly to destroy the infected cells without damaging the normal ones. Here, we obtain a bio-medical model to determine the efficiency of the usefulness of Doxorubicin (DOX) as an antitumor agent conjugated with SWCNTs with variant radii r and fullerene derivative (CN-[OH]ß). The two sub-models are obtained mathematically to evaluate the potential energy arising from the DOX-SWCNT and DOX-(CN-[OH]ß) interactions. DOX modelled as two-connected spheres, small and large, each interacting with different SWCNTs (variant radii r) and fullerene derivatives CN-[OH]ß, formed based on the number of carbon atoms (N) and the number of hydroxide molecules (OH) (ß), respectively. Based on our obtained results, we find that the most favorable carbon nanomaterial is the SWCNT (r = 15.27 Å), followed by fullerene derivatives CN-(OH)22, CN-(OH)20, and CN-(OH)24, with minimum energies of -38.27, -33.72, -32.95, and -29.11 kcal/mol.

Toxic Effect of Fullerene and Its Derivatives upon the Transmembrane ß2-Adrenergic Receptors.

Numerous experiments have revealed that fullerene (C60) and its derivatives can bind to proteins and affect their biological functions. In this study, we explored the interaction between fullerine and the ß2-adrenergic receptor (ß2AR). The MD simulation results show that fullerene binds with the extracellular loop 2 (ECL2) and intracellular loop 2 (ICL2) of ß2AR through hydrophobic interactions and π-π stacking interactions. In the C60_in1 trajectory, due to the π-π stacking interactions of fullerene molecules with PHE and PRO residues on ICL2, ICL2 completely flipped towards the fullerene direction and the fullerene moved slowly into the lipid membrane. When five fullerene molecules were placed on the extracellular side, they preferred to stack into a stable fullerene cluster (a deformed tetrahedral aggregate), and had almost no effect on the structure of ß2AR. The hydroxyl groups of fullerene derivatives (C60(OH)X, X represents the number of hydroxyl groups, X = 4, 8) can form strong hydrogen bonds with the ECL2, helix6, and helix7 of ß2AR. The hydroxyl groups firmly grasp the ß2AR receptor like several claws, blocking the binding entry of ligands. The simulation results show that fullerene and fullerene derivatives may have a significant effect on the local structure of ß2AR, especially the distortion of helix4, but bring about no great changes within the overall structure. It was found that C60 did not compete with ligands for binding sites, but blocked the ligands' entry into the pocket channel. All the above observations suggest that fullerene and its derivatives exhibit certain cytotoxicity.

Effects of Covalent Conjugates of Fullerene Derivatives with Xanthene Dyes on Activity of Ca2+-ATPase of the Sarcoplasmic Reticulum.

The effects of the newly synthesized covalent conjugates of water-soluble fullerene derivatives (WSFD) with xanthene dyes: polyanionic WSFD-fluorescein (1), polycationic WSFD-fluorescein (2), polyanionic WSFD-eosin (3), and polyanionic WSFD (4), polycationic WSFD (5), fluorescein (6) and eosin (7), on activity of the membrane-bound Ca2+-ATPase of the sarcoplasmic reticulum (SR Ca2+-ATPase) were studied. Compounds 1, 3, 4, 6, and 7 inhibit the hydrolytic function of the enzyme, the inhibition constants for these compounds are Ki=1.3×10-5 M (1), Ki=4.7×10-6 M (3), Ki=2.5×10-6 M (4), Ki=6.1×10-5 M (6), and Ki=5.8×10-6 M (7). The effects of compounds 3, 6, and 7 on the hydrolytic function of the enzyme is competitive; compounds 1 and 4 are noncompetitive. Polycationic WSFD fluorescein (2) and polycationic WSFD (5) do not affect ATP hydrolysis, but inhibit active Ca2+ transport in a concentration of 0.01 mM by 100±10 and 40±4%, respectively. Conjugates 1 and 3 completely inhibit the hydrolytic and transport functions of the enzyme in a concentration of 0.01 mM, and in a concentration of 0.001 mM inhibit active Ca2+ transport by 60±6 and 55±6% uncoupling the hydrolytic and transport functions of SR Ca2+-ATPases. The obtained results demonstrate a significant effect of the studied compounds on the active transmembrane transfer of Ca2+ and make it possible to predict the presence of antimetastatic and antiaggregatory activities of the studied compounds.

Drawing a different picture with pencil lead as matrix-assisted laser desorption/ionization matrix for fullerene derivatives.

Inspired by reports on the use of pencil lead as a matrix-assisted laser desorption/ionization matrix, paving the way towards matrix-free matrix-assisted laser desorption/ionization, the present investigation evaluates its usage with organic fullerene derivatives. Currently, this class of compounds is best analysed using the electron transfer matrix trans-2-[3-(4-tert-butylphenyl)-2-methyl-2-propenylidene] malononitrile (DCTB), which was employed as the standard here. The suitability of pencil lead was additionally compared to direct (i.e. no matrix) laser desorption/ionization-mass spectrometry. The use of (DCTB) was identified as the by far gentler method, producing spectra with abundant molecular ion signals and much reduced fragmentation. Analytically, pencil lead was found to be ineffective as a matrix, however, appears to be an extremely easy and inexpensive method for producing sodium and potassium adducts.

Synthesis and Antiviral Activity of Water-Soluble Polycarboxylic Derivatives of [60]Fullerene Loaded with 3,4-Dichlorophenyl Units.

We have synthesized a series of water-soluble polycarboxylic derivatives of [60]fullerene with a gradually changed polarity by combining three to five polar (ionic) malonate addends with two to zero hydrophobic dichlorobenzene units and explored their antiviral activity. It has been shown that decreasing the number of the ionogenic carboxylic groups in the molecules enhanced their antiviral activity against HIV-1 and suppressed their action against HIV-2. The obtained results implied that the charged states and hydrophobicity of the water-soluble polycarboxylic fullerene derivatives affect significantly their biological properties.

Effects of Fullerene Derivatives on Activity of Ca2+-ATPase of the Sarcoplasmic Reticulum and cGMP Phosphodiesterase.

We studied the effects of new water-soluble polysubstituted fullerene C60 (PFD) derivatives on activity of Ca2+-Mg2+ ATPase of the sarcoplasmic reticulum and cGMP phosphodiesterase. All examined fullerene derivatives inhibited activity of both enzymes. For instance, PFD-I, PFD-II, PFD-III, PFD-V, PFD-IX, PFD-X, and PFD-XI in a concentration of 5×10-5 M completely inhibited hydrolytic and transport functions of Ca2+-ATPase. These compounds in a concentration of 5×10-6 suppressed active transport of calcium ions by 51±5, 77±8, 52±5, 52±5, 100±10, 80±8, and 100±10%, respectively, and inhibited ATP hydrolysis by 31±3, 78±8, 18±2, 29±3, 78±8, 63±7, and 73±9%, respectively, uncoupling the hydrolytic and transport functions of the enzyme. PFD-I noncompetitive and reversibly reduced activity of Ca2+-ATPase (Ki=2.3×10-6 M). All the studied fullerene derivatives (except for PFD-VII) inhibited cGMP phosphodiesterase by more than 80% in concentration of 10-4 M and higher and by more than 50% in concentration of 10-5 M. PFD-I is a non-competitive reversible inhibitor of cGMP phosphodiesterase (Ki=7×10-6 M). These results allow us to expect antimetastatic, antiaggregatory, antihypertensive and vasodilative activity of the studied compounds.

Highly Efficient Planar Perovskite Solar Cells Via Interfacial Modification with Fullerene Derivatives.

Planar heterojunction perovskite solar cells with a high efficiency up to 17.76% are fabricated by modifying the compact TiO2 (c-TiO2) with a [6,6]-phenyl-C61-butyric acid (PCBA) monolayer. High quality CH3NH3PbI3 films can be easily fabricated on PCBA-modified c-TiO2 substrates by a one-step solution processing method. Significant improvements of the device parameters are observed after PCBA modification. A high open-circuit voltage (Voc) of 1.16 V has been achieved, indicating that the PCBA monolayer can act as a hole blocking layer to reduce the trap site density atop the c-TiO2 and the hole recombination at the c-TiO2 /perovskite interface. The enhancement of the fill factor, as well as the partial quenching of the fluorescence of perovskite after modification with PCBA, reveals that the charge extraction is improved.

Metabolite responses of cucumber on copper toxicity in presence of fullerene C60 derivatives.

Copper (Cu) toxicity in crops is a result of excessive release of Cu into environment. Little is known about mitigation of Cu toxicity through the application of carbon-based nanomaterials including water-soluble fullerene C60 derivatives. Two derivatives of fullerene were examined: polyhydroxylated C60 (fullerenol) and arginine C60 derivative. In order to study the response of Cu-stressed plants (Cucumis sativus L.) to these nanomaterials, metabolomics analysis by gas chromatography-mass spectrometry (GC-MS) was performed. Excess Cu (15 µM) caused substantial increase in xylem sap Cu, retarded dry biomass and leaf chlorosis of hydroponically grown cucumber. In Cu-stressed leaves, metabolomes was disturbed towards suppression metabolism of nitrogen (N) compounds and activation metabolism of hexoses. Also, upregulation of some metabolites involving in antioxidant defense system, such as ascorbic acid, tocopherol and ferulic acid, was occurred in Cu-stressed leaves. Hydroponically added fullerene adducts decreased the xylem sap Cu and alleviated Cu toxicity with effectiveness has been most pronounced for arginine C60 derivative. Metabolic responses of plants subjected to high Cu with fullerene derivatives were opposite to that observed under Cu alone. Fatty acids up-regulation (linolenic acid) and antioxidant molecules (tocopherol) down-regulation might indicate that arginine C60 adduct can alleviate Cu induced oxidative stress. Although fullerenol slightly improved cucumber growth, its effect on metabolic state of Cu-stressed plants was not statistically significant. We suggest that tested fullerene C60 adducts have a potential to prevent Cu toxicity in plants through a mechanism associated with their capability to restrict xylem transport of Cu from roots to shoot, and to maintain antioxidative properties of plants.

Research progress of fullerenes and their derivatives in the field of PDT.

In contemporary studies, the predominant utilization of C60 derivatives pertains to their role as photosensitizers or agents that scavenge free radicals. The intriguing coexistence of these divergent functionalities has prompted extensive investigation into water-soluble fullerenes. The photodynamic properties of these compounds find practical applications in DNA cleavage, antitumor interventions, and antibacterial endeavors. Consequently, photodynamic therapy is progressively emerging as a pivotal therapeutic modality within the biomedical domain, owing to its notable levels of safety and efficacy. The essential components of photodynamic therapy encompass light of the suitable wavelength, oxygen, and a photosensitizer, wherein the reactive oxygen species generated by the photosensitizer play a pivotal role in the therapeutic mechanism. The remarkable ability of fullerenes to generate singlet oxygen has garnered significant attention from scholars worldwide. Nevertheless, the limited permeability of fullerenes across cell membranes owing to their low water solubility necessitates their modification to enhance their efficacy and utilization. This paper reviews the applications of fullerene derivatives as photosensitizers in antitumor and antibacterial fields for the recent years.

Application of Bis-Adducts of Phenyl-C61 Butyric Acid Methyl Ester in Promoting the Open-Circuit Voltage of Indoor Organic Photovoltaics.

Fullerene-based indoor OPVs, particularly phenyl-C61 butyric acid methyl ester (PCBM), has been regarded as a prospective harvesting indoor light energy source to drive low-power consumption electronic devices such as sensors and IoTs. Due to the low tunability of its inherently spherical structure, the performance of the fullerene-based indoor OPVs seem to hit a bottleneck compared with the non-fullerene materials. Here, we explore the potential application of fullerene derivative bis-PCBM in indoor OPVs, which owns a higher the lowest unoccupied molecular orbital (LUMO) level than PCBM. The results show that when blended with PCDTBT, bis-PCBM devices yield a high VOC of up to 1.05 V and 0.9 V under AM 1.5G illumination and 1000 lx indoor light, compared with the corresponding values of 0.93 V and 0.79 V for PCBM devices. Nevertheless, the disorders in bis-PCBM suppress the JSC and FF and, therefore, result in a lower efficiency compared to PCBM devices. However, the efficiency and stability differences between the two kinds of cells were much reduced under indoor light conditions. After further optimization of the material composition and fabrication process, bis-PCBM could be an alternative to PCBM, offering great potential for indoor OPV with high performance.

Optical Properties and Light-Induced Charge Transfer in Selected Aromatic C60 Fullerene Derivatives and in Their Bulk Heterojunctions with Poly(3-Hexylthiophene).

Fullerene derivatives offer great scope for modification of the basic molecule, often called a buckyball. In recent years, they have been the subject of numerous studies, in particular in terms of their applications, including in solar cells. Here, the properties of four recently synthesized fullerene C60 derivatives were examined regarding their optical properties and the efficiency of the charge transfer process, both in fullerene derivatives themselves and in their heterojunctions with poly (3-hexylthiophene). Optical absorption, electron spin resonance (ESR), and time-resolved photoluminescence (TRPL) techniques were applied to study the synthesized molecules. It was shown that the absorption processes in fullerene derivatives are dominated by absorption of the fullerene cage and do not significantly depend on the type of the derivative. It was also found by ESR and TRPL studies that asymmetrical, dipole-like derivatives exhibit stronger light-induced charge transfer properties than their symmetrical counterparts. The observed inhomogeneous broadening of the ESR lines indicated a large disorder of all polymer-fullerene derivative blends. The density functional theory was applied to explain the results of the optical absorption experiments.

Progress in Antiviral Fullerene Research.

Unlike traditional small molecule drugs, fullerene is an all-carbon nanomolecule with a spherical cage structure. Fullerene exhibits high levels of antiviral activity, inhibiting virus replication in vitro and in vivo. In this review, we systematically summarize the latest research regarding the different types of fullerenes investigated in antiviral studies. We discuss the unique structural advantage of fullerenes, present diverse modification strategies based on the addition of various functional groups, assess the effect of structural differences on antiviral activity, and describe the possible antiviral mechanism. Finally, we discuss the prospective development of fullerenes as antiviral drugs.