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Fullerenes, particularly C60, exhibit unique properties that make them promising candidates for various applications, including drug delivery and nanomedicine. However, their interactions with biomolecules, especially proteins, remain not fully understood. This study implements both explicit and implicit C60 models into the UNRES coarse-grained force field, enabling the investigation of fullerene–protein interactions without the need for restraints to stabilize protein structures. The UNRES force field offers computational efficiency, allowing for longer timescale simulations while maintaining accuracy. Five model proteins were studied: FK506 binding protein, HIV-1 protease, intestinal fatty acid binding protein, PCB-binding protein, and hen egg-white lysozyme. Molecular dynamics simulations were performed with and without C60 to assess protein stability and investigate the impact of fullerene interactions. Analysis of contact probabilities reveals distinct interaction patterns for each protein. FK506 binding protein (1FKF) shows specific binding sites, while intestinal fatty acid binding protein (1ICN) and uteroglobin (1UTR) exhibit more generalized interactions. The explicit C60 model shows good agreement with all-atom simulations in predicting protein flexibility, the position of C60 in the binding pocket, and the estimation of effective binding energies. The integration of explicit and implicit C60 models into the UNRES force field, coupled with recent advances in coarse-grained modeling and multiscale approaches, provides a powerful framework for investigating protein–nanoparticle interactions at biologically relevant scales without the need to use restraints stabilizing the protein, thus allowing for large conformational changes to occur. These computational tools, in synergy with experimental techniques, can aid in understanding the mechanisms and consequences of nanoparticle–biomolecule interactions, guiding the design of nanomaterials for biomedical applications.

Among different inorganic and organic polarizer elements, thin-film light polarizers occupy a special place because of their flexibility, ease of integration into any optoelectronic circuit, and good functioning in the visible and near-infrared spectral range and can compete with Glan and Nicolas volumetric prisms. This paper presents the results of a study on how carbon-based nanoparticles influence on the basic properties of a well-known PVA-based polymer matrix, using which it is possible to obtain good transparency for parallel light components. An accent is made on graphene oxide nanoparticles, which are used as PVA sensitizers. It was shown for the first time that the structuring of PVA with graphene oxides allows an increased transmittance of the parallel light component to be obtained, saving the transmittance of the orthogonal one. Moreover, the graphene network can increase the mechanical strength of such thin-film PVA-based polarizers and provoke a change in the wetting angle. These advantages make it possible to use graphene oxide-structured thin-film light polarizers based on a PVA matrix as an independent optoelectronic element. Some comparative results for polarizers based on PVA-C70 structures are shown as well.

Organic electronic applications are envisioned to address broad markets, which includes flexible displays, electronic papers, sensors, disposable and wearable electronics, and medical and biophysical applications, leading to a tremendous amount of interest from both academia and industry in the study of devices. These fields of science and technology constitute interdisciplinary fields that cover physics, chemistry, biology, and materials science, leading, as a wanted output, to the elucidation of physical and chemical properties, as well as structures, fabrication, and performance evaluation of devices and the creation of new knowledge underlying the operation of organic devices using new synthesized organic materials—organic semiconductors. We testify the situation when the available organic electronic applications sometimes lack a theoretical background. The cause may be the complicated properties of disordered, weak bounded, molecular materials with properties different from their inorganic counterparts. One of the basic information-rich resources is the electronic structure of organic semiconductors, elucidated by the methods, hardly possible to be transferred from the branch of inorganic semiconductors. Electrochemical spectroscopic methods, in general, and electrochemical impedance spectroscopy, in particular, tend and seem to fill this gap. In this Perspective article, the energy resolved-electrochemical impedance spectroscopic method for electronic structure studies of surface and bulk of organic semiconductors is presented, and its theoretical and implementation background is highlighted. To show the method's properties and strength, both as to the wide energy and excessive dynamic range, the basic measurements on polymeric materials and D–A blends are introduced, and to highlight its broad applicability, the results on polysilanes degradability, gap engineering of non-fullerene D–A blends, and electron structure spectroscopy of an inorganic nanocrystalline film are highlighted. In the outlook and perspective, the electrolyte/polymer interface will be studied in general and specifically devoted to the morphological, transport, and recombination properties of organic semiconductors and biophysical materials. [ABSTRACT FROM AUTHOR]

Epitaxial Ge films were grown on Si(001) substrates by molecular beam epitaxy. During epitaxial growth, two carbon interlayers were deposited at varying substrate temperatures (140 − 620 ° C) and with varying C quantity (0 − 1.5 monolayers). The influence of the second carbon interlayer on in-plane strain was investigated using high-resolution x-ray diffraction and transmission electron microscopy (TEM). All samples exhibited compressive strain, which was attributed to substitutional incorporation of carbon atoms. In-plane strain decreases with increasing substrate temperature during carbon deposition, indicating that enhanced surface mobility of carbon adatoms leads to formation of carbon clusters. This was confirmed by cross-sectional TEM investigations. Variation of C quantity at 180 ° C reveals maximum strain at an intermediate quantity of 0.8 monolayers. Omission of the second C interlayer results in much lower strain, indicating a mismatch between the two Ge layers separated by a C interlayer. This could be used to enforce dislocation filtering following the principle of strained layer superlattices. An upper estimate of 1 × 10 − 3 was found for the mismatch strain, resulting in a critical thickness for dislocation filtering of h c = 153 nm. A sample just exceeding h c exhibited a clear dislocation reduction effect as shown by TEM. [ABSTRACT FROM AUTHOR]

We describe the development of a reactive force field for C/O systems under extreme temperatures and pressures, based on the many-body Chebyshev Interaction Model for Efficient Simulation (ChIMES). The resulting model, which targets carbon condensation under thermodynamic conditions of 6500 K and 2.5 g cm−3, affords a balance between model accuracy, complexity, and training set generation expense. We show that the model recovers much of the accuracy of density functional theory for the prediction of structure, dynamics, and chemistry when applied to dissociative condensed phase systems at 1:1 and 1:2 C:O ratios, as well as molten carbon. Our C/O modeling approach exhibits a 104 increase in efficiency for the same system size (i.e., 128 atoms) and a linear system size scalability over standard quantum molecular dynamics methods, allowing the simulation of significantly larger systems than previously possible. We find that the model captures the condensed-phase reaction-coupled formation of carbon clusters implied by recent experiments, and that this process is susceptible to strong finite size effects. Overall, we find the present ChIMES model to be well suited for studying chemical processes and cluster formation at pressures and temperatures typical of shock waves. We expect that the present C/O modeling paradigm can serve as a template for the development of a broader high pressure–high temperature force-field for condensed phase chemistry in organic materials. [ABSTRACT FROM AUTHOR]

Growth of high-quality graphene on germanium is to date only reported at growth temperatures near the substrate melting point. Direct integration of graphene growth into technological processes would, however, require a significantly lower growth temperature. Accordingly, we investigated the influence of growth temperature on the quality of graphene on Ge(001), Ge(110), and Ge(111). We found that increased defect density as indicated by Raman spectroscopy correlates with topographically protruding carbon defect clusters as indicated by scanning tunneling microscopy. The Raman quality of graphene on Ge(001) and Ge(110) grown at 850 °C is clearly limited by defects within the relatively large grains and not by grain boundaries, whereas the quality of graphene on Ge(111) additionally suffers from small grain size. We explain the decreased graphene quality by too weak substrate-mediated etching of defective carbon structures. Finally, we discuss potential ways to increase the rate of carbon etching. [ABSTRACT FROM AUTHOR]

Determining the geometry of carbon rings is an ongoing challenge. Based on our calculations at a state-of-the-art level, we found that the C20− ring possesses five bound electronic states, including a superatomic state, which is the first superatomic state found for a ring. The nature of these electronic states is discussed. Our calculation reveals a symmetry breaking of the C20− ring anion ground electronic structure occurring upon attaching an electron to the neutral ring. The discussion of the possible symmetry breaking mechanisms indicates that the shrinking and distortion of the ring upon electron attachment, leading to the symmetry breaking, is a result of the interplay between the symmetry breaking and the totally symmetric modes. The discussion enriches the palette of possible symmetry breaking phenomena in carbon clusters. [ABSTRACT FROM AUTHOR]

We present the open-source VOTCA-XTP software for the calculation of the excited-state electronic structure of molecules using many-body Green's function theory in the GW approximation with the Bethe–Salpeter equation (BSE). This work provides a summary of the underlying theory and discusses the details of its implementation based on Gaussian orbitals, including resolution-of-identity techniques and different approaches to the frequency integration of the self-energy or acceleration by offloading compute-intensive matrix operations using graphics processing units in a hybrid OpenMP/Cuda scheme. A distinctive feature of VOTCA–XTP is the capability to couple the calculation of electronic excitations to a classical polarizable environment on an atomistic level in a coupled quantum- and molecular-mechanics (QM/MM) scheme, where a complex morphology can be imported from Molecular Dynamics simulations. The capabilities and limitations of the GW–BSE implementation are illustrated with two examples. First, we study the dependence of optically active electron–hole excitations in a series of diketopyrrolopyrrole-based oligomers on molecular-architecture modifications and the number of repeat units. Second, we use the GW–BSE/MM setup to investigate the effect of polarization on localized and intermolecular charge-transfer excited states in morphologies of low-donor content rubrene–fullerene mixtures. These showcases demonstrate that our implementation currently allows us to treat systems with up to 2500 basis functions on regular shared-memory workstations, providing accurate descriptions of quasiparticle and coupled electron–hole excited states of various characters on an equal footing. [ABSTRACT FROM AUTHOR]

By presenting a theoretical steady-state rate equation analysis, we demonstrate an efficient optical power limiting in a fullerene system, which can be attributed to a reverse saturable absorption mechanism. The limiting behavior, characterized by means of the sample's transmittance, is explained via the population redistribution among singlet and triplet levels. In addition, the effects of intersystem crossing and reverse intersystem crossing rates on the limiting behavior are investigated. Our numerical results show how these rates alter the optical limiting performance; indeed, the intersystem crossing has a constructive role in decreasing the optical limiting threshold. In addition, a theoretical investigation of the z-scan technique is employed to further characterize the power limiting properties. [ABSTRACT FROM AUTHOR]

The C2 carbon cluster is found in a large variety of environments including flames, electric discharges, and astrophysical media. Due to spin-selection rules, assessing a complete overview of the dense vibronic landscape of the C 2 + cation starting from the ground electronic state X Σ g + 1 of the neutral is not possible, especially since the C 2 + ground state is of X + Σ g − 4 symmetry. In this work, a flow-tube reactor source is employed to generate the neutral C2 in a mixture of both the lowest singlet X Σ g + 1 and triplet a 3Πu electronic states. We have investigated the vibronic transitions in the vicinity of the first adiabatic ionization potential via one-photon ionization with vacuum ultraviolet synchrotron radiation coupled with electron/ion double imaging techniques. Using ab initio calculations and Franck-Condon simulations, three electronic transitions are identified and their adiabatic ionization energy is determined E i ( a + 2 Π u ← X 1 Σ g + ) = 12.440 (10) eV, E i ( X + 4 Σ g − ← a 3 Π u ) = 11.795 (10) eV, and Ei(a+2Πu ← a3Πu) = 12.361(10) eV. From the three origin bands, the following energy differences are extracted: ΔE(a − X) = 0.079(10) eV and ΔE(a+ − X+) = 0.567(10) eV. The adiabatic ionization potential corresponding to the forbidden one-photon transition X+ ← X is derived and amounts to 11.873(10) eV, in very good agreement with the most recent measurement by Krechkivska et al. [J. Chem. Phys. 144, 144305 (2016)]. The enthalpy of formation of the doublet ground state C 2 + cation in the gas phase is determined at 0 K, Δ f H 0 (0 K) ( C 2 + ( Π u 2 )) = 2019.9 (10) kJ mol−1. In addition, we report the first experimental ion yield of C2 for which only a simple estimate was used up to now in the photochemistry models of astrophysical media due to the lack of experimental data. [ABSTRACT FROM AUTHOR]

The working equations for the calculation of the electron paramagnetic resonance (EPR) g-tensor within the framework of the auxiliary density functional theory (ADFT) are presented. The scheme known as gauge including atomic orbitals (GIAOs) is employed to treat the gauge origin problem. This ADFT-GIAO formulation possesses an inherent high computational performance, allowing for the calculation of the EPR g-tensor of molecules containing some hundreds of atoms in reasonable computational time employing moderate computational resources. The effect of the use of a gauge independent auxiliary density on the quality of the g-tensor calculation for the evaluation of the exchange-correlation contribution is analyzed in this work. The best agreement with the experiment is obtained with the BLYP functional (Becke 1988 exchange and Lee-Yang-Parr correlation) in combination with a double-ζ basis set, in particular aug-cc-pVDZ. Furthermore, models of endohedral fullerenes N@Cn, with n = {60, 70, 100, 180, 240}, were used for benchmarking its computational performance. [ABSTRACT FROM AUTHOR]

The main results of non-linear optical, spectral and current–voltage characteristics research of pyridine organic conjugated molecule-carbon nanoparticles combined system have been presented. The perspective of these materials further study in global trends of modern search of materials for optical limiting has been demonstrated also in the present paper. [ABSTRACT FROM AUTHOR]

Organic semiconductors are prone to strong disorder effects that often exhibit significant dynamic characteristics. In this study, static disorder and dynamic disorder of fullerene molecules at the interface of Au(111) are directly distinguished using Scanning Tunneling Microscopy (STM) and Scanning Tunneling Spectroscopy. We consider an STM image consisting of hundreds of different molecules, as an ensemble which exhibits conductance fluctuations due to both dynamic disorder and static disorder. On the other hand, local conductance measurement of single molecules over time reflects only dynamic disorder. We demonstrate that dynamic disorder is always smaller than static disorder at the C60/Au(111) interface due to structural constraints of molecules at the interface. Dynamic disorder in our experiment is due to small librations of individual molecules that are restricted by the metal surface, while static disorder is related to different bonding orientations of the C60 cage that are frozen-in at room temperature. Our experimental results can be modeled with direct simulations of differential tunneling conductance. [ABSTRACT FROM AUTHOR]

The purpose of the research is to develop and study biocatalysts based on complexes of cysteine proteases with fullerenes and carbon nanotubes. During the formation of ficin complexes with fullerenes and carbon nanotubes, the activity of hybrid preparations was 70 and 45%, respectively. During the formation of papain complexes with fullerenes and carbon nanotubes, the proteolytic ability of the enzyme remained at the same level for the samples with fullerene and decreased by 27% for the preparations with carbon nanotubes. The formation of bromelain complexes with fullerenes and carbon nanotubes contributed to a decrease in the proteolytic activity of the biocatalyst by 18 and 48% as compared to the free enzyme. While determining the stability of complexes of nanomaterials and cysteine proteases during a 7-day incubation in 0.05 M tris-HCl buffer (pH 7.5) at 37 °C, we noticed a decrease in the proteolytic activity of the samples. Complexation with carbon nanoparticles and fullerenes increased the stability of ficin and bromelain, while the stability of papain in the complexes remained unchanged

Graphene oxide (GO) with its unique two-dimensional structure offers an emerging platform for designing advanced gas separation membranes that allow for highly selective transport of hydrogen molecules. Nevertheless, further tuning of the interlayer spacing of GO laminates and its effect on membrane separation efficiency remains to be explored. Here, positively charged fullerene C60 derivatives are electrostatically bonded to the surface of GO sheets in order to manipulate the interlayer spacing between GO nanolaminates. The as-prepared GO-C60 membranes have a high H2 permeance of 3370 GPU (gas permeance units) and an H2/CO2 selectivity of 59. The gas separation selectivity is almost twice that of flat GO membranes because of the role of fullerene. [ABSTRACT FROM AUTHOR]

Using metal coordination to assemble carbon nanodots (CND) into clusters can enhance their photophysical properties for applications in sensing and biomedicine. Water-soluble clusters of CNDs are prepared by one-step microwave synthesis starting from ethylenediaminetetraacetic acid, ethylenediamine and MnCl2·4H2O as precursors. Transmission electron microscopy and powder X-Ray diffraction techniques indicate that the resulting clusters form spherical particles of 150 nm constituted by amorphous CNDs joined together with Mn ions in a laminar crystalline structure. The nanomaterial assemblies show remarkable fluorescence quantum yields (0.17–0.20) and magnetic resonance imaging capability (r1 = 2.3-3.8 mM–1.s–1). In addition, they can be stabilized in aqueous solutions by phosphate ligands, providing a promising dual imaging platform for use in biological systems. Using metal coordination to assemble carbon nanodots (CND) into clusters can enhance their photophysical properties for applications in sensing and biomedicine. Here, carboxylate groups on the surface of carbon nanodots serve as ligands for the coordination of manganese ions, enabling the assembly of optically and magnetically active CND clusters in a one-step microwave-assisted synthesis in water. [ABSTRACT FROM AUTHOR]

Ergodicity, the central tenet of statistical mechanics, requires an isolated system to explore all available phase space constrained by energy and symmetry. Mechanisms for violating ergodicity are of interest for probing nonequilibrium matter and protecting quantum coherence in complex systems. Polyatomic molecules have long served as a platform for probing ergodicity breaking in vibrational energy transport. Here, we report the observation of rotational ergodicity breaking in an unprecedentedly large molecule, 12C60, determined from its icosahedral rovibrational fine structure. The ergodicity breaking occurs well below the vibrational ergodicity threshold and exhibits multiple transitions between ergodic and nonergodic regimes with increasing angular momentum. These peculiar dynamics result from the molecule’s distinctive combination of symmetry, size, and rigidity, highlighting its relevance to emergent phenomena in mesoscopic quantum systems. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Endohedral metallofullerenes (EMFs) are a family of molecules with metal clusters or ions encapsulated inside a fullerene cage. Their unique structures provide a powerful interface for organic chemists to manipulate metal elements. Over a decade ago, many reactions on empty fullerenes were adopted for EMFs, resulting in a series of reactions that are well‐established and reviewed in the literature. In recent years, new topics have emerged in EMF chemistry. First, new addition reactions were developed, notably some that are not based on known empty‐fullerene reactions. Second, considerable progress has been made on regioselective multi‐additions on EMFs. Finally, EMFs have been covalently conjugated with fullerene C60 to form functional materials. This Recent Advances article will focus on these new developments and discuss their implication for future directions of EMFs. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Intramolecular interactions are fundamental for the unique structures and outstanding properties of metallofullerenes. However, how the internal metal species interplay with the cluster configuration inside oxide clusterfullerenes remains poorly understood. Herein, we successfully captured two oxide clusterfullerenes with different metals, namely, Lu2O@C82 and Er2O@C82, to elucidate the role of metal species in tuning cluster configuration. The two molecules have been fully characterized by mass spectrometry, Vis‐NIR absorption spectroscopy, cyclic voltammetry, and single‐crystal X‐ray diffraction. Crystallographic data show that their isomeric cages were both determined as Cs(6)‐C82. Further structural analysis reveals that the Lu1‐O‐Lu2 angle value in Lu2O@Cs(6)‐C82 is much larger than the Er1‐O‐Er2 angle value in Er2O@Cs(6)‐C82, indicating that the configuration of the endohedral oxide clusters is flexible and dependent on the metal ion radius. Additionally, electrochemical studies suggest that the variation in entrapped metal species causes differences in redox properties, for which the first oxidation and first reduction potentials of Lu2O@Cs(6)‐C82 are shifted positively and negatively, respectively, compared to the counterparts of Er2O@Cs(6)‐C82, resulting in a larger electrochemical band‐gap. [ABSTRACT FROM AUTHOR]

In this study, we present a comprehensive investigation into the charge generation mechanism in bulk-heterojunction organic solar cells employing non-fullerene acceptors (NFAs) both with and without the presence of processing additives. While photovoltaic devices based on Y6 or BTP-eC9 have shown remarkable power conversion efficiencies, the underlying charge generation mechanism in polymer:NFA blends remains poorly understood. To shed light on this, we employ transient absorption (TA) spectroscopy to elucidate the charge transfer pathway within a blend of the donor polymer PM6 and NFAs. Interestingly, the charge carrier lifetimes of neat Y6 and BTP-eC9 are comparable, both reaching up to 20 ns. However, the PM6:BTP-eC9 blend exhibits substantially higher charge carrier generation and a longer carrier lifetime compared to PM6:Y6 blend films, leading to superior performance. By comparing TA data obtained from PM6:Y6 or PM6:BTP-eC9 blend films with and without processing additives, we observe significantly enhanced charge carrier generation and prolonged charge carrier lifetimes in the presence of these additives. These findings underscore the potential of manipulating excited species as a promising avenue for further enhancing the performance of organic solar cells. Moreover, this understanding contributes to the advancement of NFA-based systems and the optimization of charge transfer processes in polymer:NFA blends. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Intramolecular interactions are fundamental for the unique structures and outstanding properties of metallofullerenes. However, how the internal metal species interplay with the cluster configuration inside oxide clusterfullerenes remains poorly understood. Herein, we successfully captured two oxide clusterfullerenes with different metals, namely, Lu2O@C82 and Er2O@C82, to elucidate the role of metal species in tuning cluster configuration. The two molecules have been fully characterized by mass spectrometry, Vis‐NIR absorption spectroscopy, cyclic voltammetry, and single‐crystal X‐ray diffraction. Crystallographic data show that their isomeric cages were both determined as Cs(6)‐C82. Further structural analysis reveals that the Lu1‐O‐Lu2 angle value in Lu2O@Cs(6)‐C82 is much larger than the Er1‐O‐Er2 angle value in Er2O@Cs(6)‐C82, indicating that the configuration of the endohedral oxide clusters is flexible and dependent on the metal ion radius. Additionally, electrochemical studies suggest that the variation in entrapped metal species causes differences in redox properties, for which the first oxidation and first reduction potentials of Lu2O@Cs(6)‐C82 are shifted positively and negatively, respectively, compared to the counterparts of Er2O@Cs(6)‐C82, resulting in a larger electrochemical band‐gap. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Endohedral metallofullerenes (EMFs) are a family of molecules with metal clusters or ions encapsulated inside a fullerene cage. Their unique structures provide a powerful interface for organic chemists to manipulate metal elements. Over a decade ago, many reactions on empty fullerenes were adopted for EMFs, resulting in a series of reactions that are well‐established and reviewed in the literature. In recent years, new topics have emerged in EMF chemistry. First, new addition reactions were developed, notably some that are not based on known empty‐fullerene reactions. Second, considerable progress has been made on regioselective multi‐additions on EMFs. Finally, EMFs have been covalently conjugated with fullerene C60 to form functional materials. This Recent Advances article will focus on these new developments and discuss their implication for future directions of EMFs. [ABSTRACT FROM AUTHOR]

We present a comprehensive host‐guest study of four substituted and unsubstituted [10]cycloparaphenylenes with the fullerenes C60 and C70. Within this study, the influence on the complexation behavior was investigated experimentally and computationally. Due to the increased steric demand the substitution on the nanohoop results in an energetic penalty, which could be partially compensated by additional substituent‐fullerene interactions. These attractive interactions are intensified in the C70 complexes and with an increased degree of substitution. For the computational investigation conformer ensembles were taken into account, providing reliable structures with Boltzmann weighted energies. An analysis of the noncovalent interactions elucidated the origin of the enhanced substituent‐C70 interaction. The ellipsoid fullerene C70 can be considered as a π‐extended version of C60, which is able to increase the attractive van der Waals interactions within these supramolecular complexes. [ABSTRACT FROM AUTHOR]

Organic photodetectors (OPDs) with spectral response extending from ultraviolet to near‐infrared domains are of great interest for many applications. Morphological impact on the performance of photomultiplication (PM)‐type OPDs, however, is still rarely investigated so far. Herein, a non‐fullerene acceptor, Y6‐Se‐HD, is synthesized, in which heavier selenium atoms substitute the sulfur atoms in the core of Y6, and used for fabricating PM‐OPDs. The resulting devices exhibit remarkable PM effects in a very broadband spectral range covering from 320 to 1090 nm. A maximum EQE value of ≈6500% at 860 nm is achieved at a low bias of −1.0 V. As compared with the device prepared with Y6 molecules, the Y6‐Se‐HD OPDs exhibited much enhanced performance. From the morphological analysis, we infer that Y6‐Se‐HD almost covers the entire active layer and avoids the direct contact of the hole‐trapping donor polymers with the Ag electrode, thereby resulting in stronger charge trapping and preventing possible charge recombination and/or quenching. Furthermore, finer phase separation between the donor and acceptor molecules also facilitates hole trapping and strengthens the PM effects. This research highlights the importance of morphological effects on the PM‐OPDs and demonstrates one approach for controlling the device morphology. [ABSTRACT FROM AUTHOR]

The identity of active sites for redox reactions within vanadium redox flow batteries (VRFBs) isstill controversial despite decades of research into the matter. Here, we use density functional theory to examine the premise of selected surface functional groups as active sites and provide mechanistic insights into the reaction pathway for the positive electrode reaction. The adsorption of electroactive species on phenol and carbene‐like edge carbon sites was compared using model aromatic clusters. Phenol groups were not favorable sites for the chemisorption of VO2+ in either V‐down or O‐down approach In contrast, carbene‐like edge carbon sites readily adsorbed VO2+ via an oxygen‐down approach, mimicking gas‐phase CO2 adsorption mechanisms. Subsequent steps to complete the reaction pathway are a series of proton adsorptions and reaction products desorption. The rate‐determining step for a reaction pathway using an edge site is VO2+ desorption step with a Gibbs energy of activation of +84 kcal mol−1. [ABSTRACT FROM AUTHOR]

The synthesis and characterization of four dumbbell‐shaped fullerene molecules connected by isosorbide and isomannide moieties is presented. Additionally, their electrochemical behavior and their ability to form complexes with [10]cycloparaphenylene ([10]CPP) were investigated. The cyclic voltammetry (CV) results of the fullerene dumbbells demonstrate a high electron affinity, indicating their strong interaction with electron‐donating counterparts such as carbon nanorings, which possess complementary charge and shape properties. To study the thermodynamic and kinetic parameters of complexation, isothermal titration calorimetry (ITC) was employed. NMR titration experiments provided further insights into the binding stoichiometries. Two distinct approaches were utilized to create bridged structures: one based on cyclopropane and the other based on furan. Regardless of the type of linker used, all derivatives formed conventional 2 : 1 complexes denoted as [10]CPP2⊃C60derivative. However, the methano‐dumbbell molecules exhibited distinct binding behavior, resulting in the formation of mono‐ and bis‐pseudorotaxanes, as well as oligomers (polymers). The formation of linear polymers holds significant potential for applications in solar energy conversion processes. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Herein, we present a facile synthesis of amide‐type water‐soluble fullerene derivatives decorated with five residues of amino acids. As compared to the previously developed approaches, the proposed method enables usage of a broad range of amino acids, including those unstable under Friedel‐Crafts reaction conditions. Furthermore, it is fully tolerant to the nature of the sixth addend X in C60R5X precursor compounds and allows one to obtain fullerene derivatives with X=Cl, H, alkyl. The synthesized amide‐type water‐soluble fullerene derivatives demonstrated promising antiviral activities against rimantadine‐resistant influenza А/Puerto Rico/8/34 (Н1N1) virus in vitro. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The experimental investigation of rare‐earth metal‐metal bonds remains a challenge in the study of chemical bonds. Herein, we report the synthesis and characterization of a novel heteronuclear di‐metallofullerene, ScY@C3v(8)‐C82, which contains a mixed rare‐earth metal‐metal bond. ScY@C3v(8)‐C82 was successfully synthesized by arc‐discharging method and characterized by mass spectrometry, UV‐vis‐NIR spectroscopy and single‐crystal X‐ray diffraction crystallography, which unambiguously determined its molecular structure. Theoretical calculations were also performed to study the optimized positions of Sc‐Y metallic dimer and the electronic configuration. The combined experimental and theoretical results confirmed that both Sc and Y atoms transfer two electrons to the C3v(8)‐C82 cage, i.e., (ScY)4+@(C3v(8)‐C82)4–. In particular, a covalent Sc‐Y σ2 bond, which has never been reported before, is proven to be formed inside C3v(8)‐C82 fullerene cage. This work presents a novel di‐metallofullerene containing mixed rare‐earth metal‐metal bond and expands the understanding of metal‐metal bonding of rare earth elements. [ABSTRACT FROM AUTHOR]

Background: The system of self-consistent models is an attempt to develop a tool to assess the predictive potential of various approaches by considering a group of random distributions of available data into training and validation sets. Considering many different splits is more informative than considering a single model. Methods: Models studied here build up for solubility of fullerenes C60 and C70 in different organic solvents using so-called quasi-SMILES, which contain traditional simplified molecular input-line entry systems (SMILES) incorporated with codes that reflect the presence of C60 and C70. In addition, the fragments of local symmetry (FLS) in quasi-SMILES are applied to improve the solubility's predictive potential (expressed via mole fraction at 298'K) models. Results: Several versions of the Monte Carlo procedure are studied. The use of the fragments of local symmetry along with a special vector of the ideality of correlation improves the predictive potential of the models. The average value of the determination coefficient on the validation sets is equal to 0.9255 ± 0.0163. Conclusions: The comparison of different manners of the Monte Carlo optimization of the correlation weights has shown that the best predictive potential was observed for models where both fragments of local symmetry and the vector of the ideality of correlation were applied. [ABSTRACT FROM AUTHOR]

I have computed the matching polynomials of a number of isomers of fullerenes of various sizes with the objective of developing molecular descriptors and similarity measures for isomers of fullerenes on the basis of their matching polynomials. Two novel matching polynomial-based topological descriptors are developed, and they are demonstrated to have the discriminating power to contrast a number of closely related isomers of fullerenes. The number of ways to place up to seven disjoint dimers on fullerene isomers are shown to be identical, as they are not structure-dependent. Moreover, similarity matrices that provide quantitative similarity measures among a given set of isomers of fullerenes are developed from their matching polynomials and are shown to provide robust quantitative measures of similarity. [ABSTRACT FROM AUTHOR]

Metal cyanide clusterfullerenes (CYCFs) are formed via the encapsulation of a single metal atom and a cyanide unit inside fullerene cages, endowing them with excellent properties in various applications. In this work, we report the synthesis, isolation, and characterizations of the first cases of thulium (Tm)-based CYCFs with the popular C82 carbon cages. The structural elucidation of the two TmCN@C82 isomers was achieved via diverse analytical techniques, including mass spectrometry, Vis-NIR spectroscopy, single-crystal X-ray crystallography, and cyclic voltammetry. The crystallographic analyses unambiguously confirmed the molecular structures of the two TmCN@C82 isomers as TmCN@Cs(6)-C82 and TmCN@C2v(9)-C82. Both TmCN clusters adopt a well-established triangular configuration, with the Tm ion located on the symmetrical plane of the carbon cages. The electronic structures of both TmCN@C82 isomers adopt a Tm3+(CN)−@(C82)2− configuration, exhibiting characteristic spectral and electrochemical properties reminiscent of divalent endohedral metallofullerenes (EMFs). Intriguingly, unlike the divalent Tm2+ ion observed in the mono-metallofullerenes Tm@C2n, a higher oxidation state of Tm3+ is identified in the monometallic TmCN cluster due to bonding with the cyanide anion. This result provides valuable insight into the essential role of the non-metallic endo-units in governing the oxidation state of the metal ion and the electronic behaviors of EMFs. [ABSTRACT FROM AUTHOR]

A series of ambipolar covalently linked oligothiophene‐fullerene dyads have been synthesized by systematical structural variations. In this respect, the length of linker between donor and acceptor unit was altered and in a second series the terminal acceptor units in the donor unit of the dyads were varied. Characterization of the optical and redox properties gave valuable structure‐property relationships and were correlated to the photovoltaic performance in single‐material organic solar cells, in which power conversion efficiencies of up to 4.3 % were reached. [ABSTRACT FROM AUTHOR]

Here the supramolecular liquid crystalline (LC) phase behavior of a series of fullerene block molecules was investigated regarding spacer length, alkyl tail length and temperature. These compounds exhibit several lamellar LC phases with different packings of self‐organized fullerene two‐dimensional (2D) crystals. With a short hexamethylene spacer, they form sandwich‐like structures with triple or quadruple fullerene layers. By increasing the spacer length to 10 or 12 carbons, a composite layers‐in‐lamella superlattice structure with alternating soft hydrocarbon single layers and fullerene single or double layers was obtained. As the molecular configurational freedom between incompatible moieties was enhanced by the elongated spacer, the required cross‐sectional fullerene‐to‐hydrocarbon ratio for the superlattice could be achieved despite of different volume fractions of the blocks. The superlattice phase range is efficiently widened by the design principle of constructing LC molecules with a long spacer, which also provides a facile way to tailor novel superstructures. [ABSTRACT FROM AUTHOR]

Carbon atoms can connect with themselves and with other atoms (both electronegative and electropositive elements) in various ways. Thanks to these abilities, the diversity of carbon compounds is increasing day by day. This growth was even faster after the discovery of carbon nanoallotropes, i.e. carbon nanotubes, fullerenes, and graphene. At present, these carbon nanoallotropes are widely studied, and new hybrid structures have been synthesized based on these nanoallotropes. Hybrid structures formed by the covalent bond of fullerenes to the outside carbon nanotubes are called carbon nanobuds (CNBs). Development of synthesis methods, computational calculations, and the study of CNB properties was much faster than other hybrid structures. However, only fewer articles on CNBs have been published in recent years. CNBs show a synergistic effect and have the unique properties of the carbon nanoallotropes from which they formed. This review discusses CNBs and reports the recent research on CNBs, mostly after 2016. [ABSTRACT FROM AUTHOR]

This study presents the largest mid-infrared spectral catalogue of Herbig Ae/Be stars to date, containing the Spitzer Infrared Spectrograph spectra of 126 stars. Based on the catalogue analysis, two prominent infrared vibrational modes of C60 bands at 17.4 and 18.9 μm are detected in the spectra of nine sources, while 7.0 μm feature is identified in the spectra of HD 319896. The spectral index analysis and the comparison of the known sources with C60 features indicated that there exist two different types of emission classes among the sample of stars. The infrared spectra of six Herbig Ae/Be stars in this study resemble that of reflection nebulae, and their association with previously known reflection nebulae is confirmed. In the case of three Herbig Ae/Be stars, we report the tentative evidence of C60 emission features originating from the circumstellar disc or nearby diffused emission region. The detection fraction of C60 in the total HAeBe star sample is ∼7 per cent, whereas the detection fraction is 30 per cent for HAeBe stars associated with nebulosity. In the catalog, C60 is exclusively present in the circumstellar regions of B type Herbig Ae/Be stars, with no evidence of its presence detected in stars with later spectral types. The present study has increased the number of young stellar objects and reflection nebulae detected with C60 multifold, which can help in understanding the excitation and formation pathway of the species. [ABSTRACT FROM AUTHOR]

In this paper, we report a wide band spectrum tri-receptor quaternary organic photodetector (OPD) based on the additional two non-fullerene acceptor materials, ITIC and IEICO-4F, with the polymer material P3HT as donor and the fullerene PC61BM as the first acceptor. The second acceptor ITIC and the third accptor IEICO-4F, with different molecular structures and absorption, were introduced into the conventional system P3HT:PC61BM to improve narrow response spectral range and the uneven response of OPDs. The experiments results show, that proposed non-fullerene acceptor materials of the narrow optical band gap were successful to broaden the absorption spectral range to near infrared. Respectively, the responses (R) and external quantum efficiency at 630, 530, and 460 nm, are up to 0.293 A W−1, 0.288 A W−1, 0. 243 A W−1, and 58%, 67%, and 66%. The quaternary OPDs achieve significant response spectrum across the 400–950 nm range with the specific detection rate (D *) exceeding 1012 Jones. It demonstrates that expanding spectrum non-fullerene materials ITIC and IEICO-4F can improve the mixing degree of the mixed materials, decrease agglomeration brought on by single widening excess, and increase spectrum absorption and moderate non-uniform response. The exciton dissociation efficiency is considerably increased by simultaneous charge transfer between the receptors and the receptors in the active layer. Moreover, the carrier mobility is improved, bimolecular recombination is suppressed. [ABSTRACT FROM AUTHOR]

The photocatalytic degradation of formaldehyde by graphite-like C3N4 is one of the most attractive and environmentally friendly strategies to address the significant threat to human health posed by indoor air pollutants. Despite its potential, this degradation process still faces issues with suboptimal efficiency, which may be attributed to the rapid recombination of photogenerated excitons and the broad band gap. As a proof of concept, a series of graphite-like C3N4@C60 composites combining graphite-like C3N4 and C60 was developed via an in situ generation strategy. The obtained graphite-like C3N4@C60 composites exhibited a remarkable increase in the photocatalytic degradation efficiency of formaldehyde, of up to 99%, under visible light irradiation, outperforming pure graphite-like C3N4 and C60. This may be due to the composites' enhanced built-in electric field. Additionally, the proposed composites maintained a formaldehyde removal efficiency of 84% even after six cycles, highlighting their potential for indoor air purification and paving the way for the development of efficient photocatalysts. [ABSTRACT FROM AUTHOR]

• Designing of eight new acceptors (MS1-MS8) for OSCs. • Investigation of electronic and photophysical properties. • Better λ max , TDM, E g , PDOS, MEP, and E b than R. • A better choice for high-performance solar cells. Herein, we report the end-capped modification of the recently reported acceptor CH1007. Considering the importance of non-fullerene acceptors, we theoretically designed a series of benzo-thiadiazole core-based acceptors (MS1-MS8) to enhance the photophysical, and photovoltaic properties of the acceptors. In this study, properties like frontier molecular orbitals, maximum absorption, transition density matrix, open-circuit voltage, binding and excitation energies, dipole moment, and partial density of states were estimated by density functional theory (DFT) and time-dependent density functional theory (TD-DFT) using B3LYP functional with bases set 6-31G(d,p). When studied computationally, all engineered compounds exhibited red-shift in the absorption spectrum and λ max lie in the range of 734–900 nm, compared to the reference compound (λ max = 735 nm). The designed acceptors exhibited low reorganizational energies (better charge transfer property), low binding and excitation energies besides narrow HOMO-LUMO bandgap. Moreover, the donor–acceptor complexes of the designed acceptors MS1 and MS4 have been studied with well-known standard donors PTB7-Th & PM6. The distribution of electron density in the resultant donor–acceptor complexes showed successful shift of electron density from donor moiety to acceptor moiety. The results revealed that such type of end-capped modifications in acceptors can lead to better photophysical and optoelectronic properties. So, designed compounds have potential to enhance the capacity of acceptor molecules and are therefore, suggested for the development of more efficient organic solar cells (OSCs). [ABSTRACT FROM AUTHOR]

Symmetry of the icosahedron group is a basic principle producing the analytical description of the fullerene by means of the theory of molecular orbitals. Further development of the fullerene model requires consideration of the half-integer statistics of the electron states. Double group of the icosahedron describes both statistics cases, but we use only fermions case, in other words, the spinor representation of the icosahedron group. In this representation, it is possible to remove restriction defining the parity of the wave function coordinate part and to build a table of characters for arbitrary meaning of the total momentum. Symmetry of the icosahedron produces algebraic structure of the residue ring on the modulo 5, when using momentum projection on chosen axis. If the momentum projection equals both ±5/2 the states come into one representation. If the momentum projection by absolute value is higher 5/2, the wave function occupies state with several entangled spinor. [ABSTRACT FROM AUTHOR]

Since the experimental works published by Ugarte in 1993, nested almost perfect graphitic spheres have been generated in the condensed phase by irradiation with high-energy electrons of graphitic particles. The quasi-spherical shapes of these molecular systems were more marked than those obtained by Ijima by applying the arc-discharge method to amorphous carbon films. Although Ugarte was able to describe the influence of parameters such as temperature and dose of electronic radiation on the transformation of these structures, theoretically it has not been possible to explain the causes of the triggering of the above-mentioned process because of the complexity of these systems. Using a computational method based on density functional theory with tight-binding approximation (DFTB), the geometries of fullerenes of order n ≤ 6 (2160 atoms) and carbon nano-onions (CNOs) of up to five layers were optimized, and the different energetic and geometric parameters of fullerenes and polyhedral CNOs were calculated. By introducing in the structure of these nanomaterials the point defects that are commonly produced during their irradiation (monovacancies, divacancies, and Stone–Wales), the possible structural deformations caused in these arrangements, as well as the formation energies were analyzed. The results obtained allow us to verify that p - p divacancies can modify the outermost nano-onion layers with an effect similar to that described experimentally by Ugarte. [ABSTRACT FROM AUTHOR]

Context: The present study aims to improve the performance of optoelectronics and photovoltaics by constructing an acceptor–donor-acceptor (A-D-A) molecule with a fullerene-free acceptor moiety. The study utilizes malononitrile and selenidazole derivatives to tailor the molecule for enhanced photovoltaic abilities. The study analyzes molecular properties and parameters like charge density, charge transport, UV absorption spectra, exciton binding energies, and electron density difference maps to determine the effectiveness of the tailored derivatives. Methods: To optimize the geometric structures, the study used four different functionals (B3LYP, CAM-B3LYP, MPW1PW91, and ɷB97XD) along with a double zeta valence basis set 6-31G(d, p) basis set. The study compared the results of the tailored derivatives with a reference molecule (R-P2F) to determine improvements in performance. The light harvesting efficiency of the molecules was analyzed by performing simulations in the gas and solvent phases (chloroform) based on the spectral overlap between the solar irradiance and the absorption spectra of the molecules. The open-circuit voltage (VOC) of each molecule was also analyzed, representing the maximum voltage that can be obtained from the cell under illuminated conditions. The findings indicated that the M1-P2F designed derivative is a more effective, with energy gap of 2.14 eV, and suitable candidate for non-fullerene organic solar cell application, based on various analyses such as power conversion efficiency, quantum chemical reactivity parameters, and electronic features. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Herein, we present a facile synthesis of amide‐type water‐soluble fullerene derivatives decorated with five residues of amino acids. As compared to the previously developed approaches, the proposed method enables usage of a broad range of amino acids, including those unstable under Friedel‐Crafts reaction conditions. Furthermore, it is fully tolerant to the nature of the sixth addend X in C60R5X precursor compounds and allows one to obtain fullerene derivatives with X=Cl, H, alkyl. The synthesized amide‐type water‐soluble fullerene derivatives demonstrated promising antiviral activities against rimantadine‐resistant influenza А/Puerto Rico/8/34 (Н1N1) virus in vitro. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The experimental investigation of rare‐earth metal‐metal bonds remains a challenge in the study of chemical bonds. Herein, we report the synthesis and characterization of a novel heteronuclear di‐metallofullerene, ScY@C3v(8)‐C82, which contains a mixed rare‐earth metal‐metal bond. ScY@C3v(8)‐C82 was successfully synthesized by arc‐discharging method and characterized by mass spectrometry, UV‐vis‐NIR spectroscopy and single‐crystal X‐ray diffraction crystallography, which unambiguously determined its molecular structure. Theoretical calculations were also performed to study the optimized positions of Sc‐Y metallic dimer and the electronic configuration. The combined experimental and theoretical results confirmed that both Sc and Y atoms transfer two electrons to the C3v(8)‐C82 cage, i.e., (ScY)4+@(C3v(8)‐C82)4–. In particular, a covalent Sc‐Y σ2 bond, which has never been reported before, is proven to be formed inside C3v(8)‐C82 fullerene cage. This work presents a novel di‐metallofullerene containing mixed rare‐earth metal‐metal bond and expands the understanding of metal‐metal bonding of rare earth elements. [ABSTRACT FROM AUTHOR]

Non-fullerene based organic solar cells display a high initial power conversion efficiency but continue to suffer from poor thermal stability, especially in case of devices with thick active layers. Mixing of five structurally similar acceptors with similar electron affinities, and blending with a donor polymer is explored, yielding devices with a power conversion efficiency of up to 17.6%. The hexanary device performance is unaffected by thermal annealing of the bulk-heterojunction active layer for at least 23 days at 130 °C in the dark and an inert atmosphere. Moreover, hexanary blends offer a high degree of thermal stability for an active layer thickness of up to 390 nm, which is advantageous for high-throughput processing of organic solar cells. Here, a generic strategy based on multi-component acceptor mixtures is presented that permits to considerably improve the thermal stability of non-fullerene based devices and thus paves the way for large-area organic solar cells. Non-fullerene-based organic solar cells generally suffer from poor thermal stability and especially in case of devices with thick active layers. Here, the authors report hexanary blends based on multi-component acceptor mixtures with a device efficiency of 17.6% and thermally stability for 23 days at 130 °C. [ABSTRACT FROM AUTHOR]

One‐dimensional (1D) magnetoelectric multiferroics are promising multifunctional materials for miniaturized sensors, actuators, and memories. However, 1D materials with both ferroelectricity and ferromagnetism are quite rare. Herein, using first‐principles calculations, a series of fullerene‐based 1D chains, namely U2C@C80‐M (M = Cr, Mn, Mo, and Ru) 1D chains with both ferroelectric (FE) and ferromagnetic (FM) properties is designed. Compared to individual U2C@Ih(7)‐C80, the spontaneous polarization (Ps) in 1D chains is enhanced by about two to four times owing to the interaction between U2C@Ih(7)‐C80 fullerene and M (M = Cr, Mn, Mo, and Ru) atoms. Meanwhile, the introduction of transition metal atoms dopes electrons into U's 5f orbitals, leading to numerous intriguing magnetic properties, such as U2C@C80‐Cr and U2C@C80‐Mo as 1D ferromagnetic semiconductors, U2C@C80‐Ru as 1D ferrimagnetic (FiM) semiconductor, and U2C@C80‐Mn as 1D antiferromagnetic (AFM) semiconductor. Excitingly, it is found that magnetic ordering and electrical polarization can be modulated independently by linking different transition metal atoms. These findings not only broaden the range of 1D multiferroic materials, but also provide promising candidates for novel electronic and spintronic applications. [ABSTRACT FROM AUTHOR]

Fe−N−C catalysts with single‐atom Fe−N4 configurations are highly needed owing to the high activity for oxygen reduction reaction (ORR). However, the limited intrinsic activity and dissatisfactory durability have significantly restrained the practical application of proton‐exchange membrane fuel cells (PEMFCs). Here, we demonstrate that constructing adjacent metal atomic clusters (ACs) is effective in boosting the ORR performance and stability of Fe−N4 catalysts. The integration of Fe−N4 configurations with highly uniform Co4 ACs on the N‐doped carbon substrate (Co4@/Fe1@NC) is realized through a "pre‐constrained" strategy using Co4 molecular clusters and Fe(acac)3 implanted carbon precursors. The as‐developed Co4@/Fe1@NC catalyst exhibits excellent ORR activity with a half‐wave potential (E1/2) of 0.835 V vs. RHE in acidic media and a high peak power density of 840 mW cm−2 in a H2−O2 fuel cell test. First‐principles calculations further clarify the ORR catalytic mechanism on the identified Fe−N4 that modified with Co4 ACs. This work provides a viable strategy for precisely establishing atomically dispersed polymetallic centers catalysts for efficient energy‐related catalysis. [ABSTRACT FROM AUTHOR]

Background: Being a scavenger of free radicals, C60 fullerenes can influence on the physiological processes in skeletal muscles, however, the effect of such carbon nanoparticles on muscle contractility under acute muscle inflammation remains unclear. Thus, the aim of the study was to reveal the effect of the C60 fullerene aqueous solution (C60FAS) on the muscle contractile properties under acute inflammatory pain. Methods: To induce inflammation a 2.5% formalin solution was injected into the rat triceps surae (TS) muscle. High-frequency electrical stimulation has been used to induce tetanic muscle contraction. A linear motor under servo-control with embedded semi-conductor strain gauge resistors was used to measure the muscle tension. Results: In response to formalin administration, the strength of TS muscle contractions in untreated animals was recorded at 23% of control values, whereas the muscle tension in the C60FAS-treated rats reached 48%. Thus, the treated muscle could generate 2-fold more muscle strength than the muscle in untreated rats. Conclusions: The attenuation of muscle contraction force reduction caused by preliminary injection of C60FAS is presumably associated with a decrease in the concentration of free radicals in the inflamed muscle tissue, which leads to a decrease in the intensity of nociceptive information transmission from the inflamed muscle to the CNS and thereby promotes the improvement of the functional state of the skeletal muscle. [ABSTRACT FROM AUTHOR]

Efforts over 40 yr still leave the source of astronomical infrared emission bands largely unidentified. Here, we report the first laboratory infrared (6–25 μ m) spectra of gas-phase fullerene-metal complexes, [C60-Metal]+ (Metal = Fe, V) and show with density functional theory calculations that complexes of C60 with cosmically abundant metals, including Li, Na, K, Mg, Ca, Al, V, and Fe, all have similar spectral patterns. Comparison with observational infrared spectra from several fullerene-rich planetary nebulae demonstrates a strong positive linear cross-correlation. The infrared features of [C60-Metal]+ coincide with four bands attributed earlier to neutral C60 bands and in addition also with several bands unexplained to date. Abundance and collision theory estimates indicate that [C60-Metal]+ could plausibly form and survive in astrophysical environments. Hence, [C60-Metal]+ are proposed as promising carriers, in supplement to C60, of observational bands, potentially representing the largest molecular species in space other than C60, C60+, and C70. [ABSTRACT FROM AUTHOR]

C60 donor dyads in which the carbon cage is covalently linked to an electron‐donating unit have been discussed as one possibility for an electron‐transfer system, and it has been shown that spherical [Ge9] cluster anions show a close relation to fullerenes with respect to their electronic structure. However, the optical properties of these clusters and of functionalized cluster derivatives are almost unknown. We now report on the synthesis of the intensely red [Ge9] cluster linked to an extended π‐electron system. [Ge9{Si(TMS)3}2{CH3C=N}‐DAB(II)Dipp]− (1−) is formed upon the reaction of [Ge9{Si(TMS)3}2]2− with bromo‐diazaborole DAB(II)Dipp‐Br in CH3CN (TMS=trimethylsilyl; DAB(II)=1,3,2‐diazaborole with an unsaturated backbone; Dipp=2,6‐di‐iso‐propylphenyl). Reversible protonation of the imine entity in 1− yields the deep green, zwitterionic cluster [Ge9{Si(TMS)3}2{CH3C=N(H)}‐DAB(II)Dipp] (1‐H) and vice versa. Optical spectroscopy combined with time‐dependent density functional theory suggests a charge‐transfer excitation between the cluster and the antibonding π* orbital of the imine moiety as the cause of the intense coloration. An absorption maximum of 1‐H in the red region of the electromagnetic spectrum and the corresponding lowest‐energy excited state at λ=669 nm make the compound an interesting starting point for further investigations targeting the design of photo‐active cluster compounds. [ABSTRACT FROM AUTHOR]

Carbon nano‐onions (CNOs) as a novel form of carbon materials hold peculiar structural features but their electrocatalytic applications are largely discouraged by the demanding synthesis conditions (e.g., ≥1500 °C and vacuum). Using C60 fullerene molecules as the sacrificial seeds and melamine as the main feedstock, herein, a novel strategy for the facile construction of CNOs nanoparticles is presented with ultrafine sizes (≈5 nm) at relatively low temperatures (≤900 °C) and atmospheric pressure. During the calcination, in‐depth characterizations reveal that C60 can retain the melamine‐derived graphitic carbon nitride from complete sublimation at high temperatures (≥700 °C). Owing to the N removal and subsequent pentagon generation, severely deformed graphitic fragments together with the disintegrated C60 molecules merge into larger sized nanosheets with high curvature, eventually leading to the formation of N‐doped defect‐rich CNOs. Owing to the integration of multiple favorable structural features of pentagons, edges, and N dopants, the CNOs obtained at 900 °C present superior oxygen reduction half‐wave potential (0.853 VRHE) and zinc–air cathode performance to the commercial Pt/C (0.838 VRHE). Density functional theory calculation further uncovers that the carbon atoms adjacent to the N‐doped edged pentagons are turned into the ORR‐active sites with O2 protonation as the rate‐determining step. [ABSTRACT FROM AUTHOR]