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This paper reports the discovery of a magnetophotoluminescence response in metallofullerene Y3N@C80 triggered by the triplet excited state. In experiments, Y3N@C80 exhibits magnetic field‐dependent (0→±42 T) phosphorescence emission at 4.2 K. Crucially, with increasing magnetic field, the phosphorescence peaks shift to longer wavelengths owing to the Zeeman effect. Further, a nanoring of [9]CPPH is employed to modulate the magnetophotoluminescence response of Y3N@C80 through host−guest interaction. The circularly polarized phosphorescence spectra of Y3N@C80 and Y3N@C80⊂[9]CPPH are investigated to further reveal their magnetophotoluminescence properties using the technique of field‐induced circular polarization (FICPO). These results show that metallofullerene Y3N@C80 with magnetophotoluminescence response has potential applications in spin‐related optical devices and quantum technology. [ABSTRACT FROM AUTHOR]

Endohedral metallofullerenes have excellent redox properties, which can be used to vary their reactivity to certain classes of molecules, such as alkyl halides. In this study, the thermal reaction of the La@C2v-C82 anion with benzyl bromide derivatives 1 at 110 °C afforded single-bonded adducts 2–5 with high regioselectivity. The products were characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and visible–near infrared spectroscopy. The reaction of La@C2v-C82 with alkyl halides using the same conditions showed no consumption of La@C2v-C82, indicating that the reactivity of La@C2v-C82 toward alkyl halides was effectively increased by one-electron reduction. Single-crystal X-ray diffraction analysis of the single-bonded adduct 3a revealed the addition site of the p-methoxybenzyl group on La@C2v-C82. Theoretical calculations indicated that the addition site carbons in neutral La@C2v-C82 have high spin density, whereas those in the La@C2v-C82 anion do not have high charge densities. Thus, the reaction is believed to occur via electron transfer, followed by the radical coupling of La@C2v-C82 and benzyl radicals, rather than by bimolecular nucleophilic substitution reaction of La@C2v-C82 anion with 1.

The development of low-cost, and highly active catalysts for electrocatalytic hydrogen evolution process is of great interest. Exohedral first row transition metal doped fullerenes based single atom catalysts (SACs) are expected to replace precious metal catalysts for sustainable and large-scale commercial scalability of hydrogen generation. Herein, a series of ten metal (Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu & Zn) single atoms doped C 60 fullerenes (metallofullerenes) are screened for hydrogen evolution reaction. All the studied metallofullerenes are optimized with the various possible spin states and the most stable spin states among them are selected for further analysis. The stability of electrocatalysts is evaluated via interaction energy analysis, which reveals that all the designed metallofullerenes are thermodynamically stable (−0.24 to −4.30 eV). The hydrogen adsorption (E ads) and Gibbs free energy results reveal that Fe@C 60 complex has the best catalytic activity for hydrogen evolution process with optimal ΔG H value of 0.08 eV. FMO analysis declares appreciable variations in electronic properties of C 60 fullerene upon doping. Moreover, density of states (DOS) analysis also corroborates with FMO analysis for designed metallofullerene (M@C 60) catalysts and HM@C 60 complexes. Exchange current density is plotted as a function free energy (ΔG H) for hydrogen evolution process over designed metallofullerene. The volcano plot reveals the near thermoneutral behavior of Fe@C 60 catalyst for hydrogen evolution reaction. Overall, results presented here for systematic screening of potential HER from metallofullerene based single atom catalysis can remarkably contribute to the design and fabrication of electrocatalysts. [Display omitted] • HM@C60 adsorption energy analysis of resulted complexes show that they are thermodynamically stable. • Superior catalytic activity towards HER is observed by Fe@C 60 due to least value of Gibbs free energy (0.08 eV). • The volcano plot reveals that Fe@C60 exhibits near thermoneutral activity for HER. • The study reveals the potential of low cost and earth abundant transition metal to act as SACs for HER. [ABSTRACT FROM AUTHOR]

Synthesis of molecular compounds with metal–metal bonds between 4f elements is recognized as one of the fascinating milestones in lanthanide metallochemistry. The main focus of such studies is on heavy lanthanides due to the interest in their magnetism, while bonding between light lanthanides remains unexplored. In this work, the Nd─Nd bonding in Nd‐dimetallofullerenes as a case study of metal–metal bonding between early lanthanides is demonstrated. Combined experimental and computational study proves that pristine Nd2@C80 has an open shell structure with a single electron occupying the Nd─Nd bonding orbital. Nd2@C80 is stabilized by a one‐electron reduction and further by the electrophilic CF3 addition to [Nd2@C80]−. Single‐crystal X‐ray diffraction reveals the formation of two Nd2@C80(CF3) isomers with D5h‐C80 and Ih‐C80 carbon cages, both featuring a single‐electron Nd─Nd bond with the length of 3.78–3.79 Å. The mutual influence of the exohedral CF3 group and endohedral metal dimer in determining the molecular structure of the adducts is analyzed. Unlike Tb or Dy analogs, which are strong single‐molecule magnets with high blocking temperature of magnetization, the slow relaxation of magnetization in Nd2@Ih‐C80(CF3) is detectable via out‐of‐phase magnetic susceptibility only below 3 K and in the presence of magnetic field. [ABSTRACT FROM AUTHOR]

Abstract Synthesis of molecular compounds with metal–metal bonds between 4f elements is recognized as one of the fascinating milestones in lanthanide metallochemistry. The main focus of such studies is on heavy lanthanides due to the interest in their magnetism, while bonding between light lanthanides remains unexplored. In this work, the Nd─Nd bonding in Nd‐dimetallofullerenes as a case study of metal–metal bonding between early lanthanides is demonstrated. Combined experimental and computational study proves that pristine Nd2@C80 has an open shell structure with a single electron occupying the Nd─Nd bonding orbital. Nd2@C80 is stabilized by a one‐electron reduction and further by the electrophilic CF3 addition to [Nd2@C80]−. Single‐crystal X‐ray diffraction reveals the formation of two Nd2@C80(CF3) isomers with D5h‐C80 and Ih‐C80 carbon cages, both featuring a single‐electron Nd─Nd bond with the length of 3.78–3.79 Å. The mutual influence of the exohedral CF3 group and endohedral metal dimer in determining the molecular structure of the adducts is analyzed. Unlike Tb or Dy analogs, which are strong single‐molecule magnets with high blocking temperature of magnetization, the slow relaxation of magnetization in Nd2@Ih‐C80(CF3) is detectable via out‐of‐phase magnetic susceptibility only below 3 K and in the presence of magnetic field.

Relative populations of the four energy-lowest isolated-pentagon-rule (IPR) isomers of Y@C82 under the high-temperature synthetic conditions are computed using the Gibbs energy based on characteristics from the density functional theory calculations (B3LYP/6–31G * ∼ SDD entropy, B3LYP/6–31G * ∼ SDD and B2PLYPD/6–31 + G * ∼ SDD energetics). Two major species are predicted, Y@ C 2 v ; 9 -C82 and Y@ C s (c) ; 6 -C82, their calculated equilibrium relative populations agreeing with observations. [ABSTRACT FROM AUTHOR]

Soot-containing terbium (Tb)-embedded fullerenes were prepared by evaporation of Tb4O7-doped graphite rods in an electric arc discharge chamber. After 1,2,4-trichlorobenzene extraction of the soot and rotary evaporation of the extract, a solid product was obtained and then dissolved into toluene by ultrasonication. Through a three-stage high-pressure liquid chromatographic (HPLC) process, Tb@C82 (I, II) isomers were isolated from the toluene solution of fullerenes and metallofullerenes. With the success of the growth of cocrystals of Tb@C82 (I, II) with Ni(OEP), the molecular structures of Tb@C82 (I) and Tb@C82 (II) were confirmed to be Tb@C2v(9)-C82 and Tb@Cs(6)-C82, respectively, based on crystallographic data from X-ray single-crystal diffraction. Moreover, it was found that Tb@C82 (I, II) isomers demonstrated different packing behaviors in their cocrystals with Ni(OEP). Tb@C2v(9)-C82 forms a 1:1 cocrystal with Ni(OEP), in which Tb@C2v(9)-C82 is aligned diagonally between the Ni(OEP) bilayers to form zigzag chains. In sharp contrast, Tb@Cs(6)-C82 forms a 2:2 cocrystal with Ni(OEP), in which Tb@Cs(6)-C82 forms a centrosymmetric dimer that is aligned linearly with Ni(OEP) pairs to form one-dimensional structures in the a–c lattice plane. In addition, the distance of a Ni atom in Ni(OEP) to the Cs(6)-C82 cage is much shorter than that to the C2v(9)-C82 one, indicative of a stronger π-π interaction between Ni(OEP) and the C82 carbon cage in the cocrystal of Tb@CS(6)-C82 and Ni(OEP). Density functional theory calculations reveal that the regionally selective dimerization of Tb@CS(6)-C82 is the result of a dominant unpaired spin existing on a particular C atom of the CS(6)-C82 cage. [ABSTRACT FROM AUTHOR]

This report deals with the quantum-chemical evaluation of the energetics and thermodynamics of the simultaneous encapsulation of HF and H 2 O by the IPR (isolated pentagon rule) C 70 fullerene cage, yielding H 2 O · HF @ C 70 species which were synthesized and characterized recently, thus further expanding the family of fullerene endohedrals with non-metallic encapsulates. The structures were optimized at the DFT (density functional theory) M06-2X/6-31++G** level. The encapsulation energetics were further refined by the advanced B2PLYPD/6-31++G** and B2PLYPD/6-311++G** methods. After enhancement of the B2PLYPD/6-311++G** encapsulation energy for the BSSE and steric corrections, the encapsulation energy gain was obtained, as 26 kcal/mol. The equilibrium encapsulation thermodynamics were described using the M06-2X/6-31++G** partition functions. The results correspond to our previous evaluations for the water dimer encapsulation by C 84 cages. [ABSTRACT FROM AUTHOR]

Spin-based interdisciplinary research has attracted considerable attention, and various applications in magnetic memory, quantum science, and precision measuring technology have been reported. In this study, we induced a fluorescence property in a spin-active molecule by supramolecular assembly and realized a synergistic modulation of its spin and fluorescence properties. A Saturn-shaped supramolecular complex was synthesized using a spin-active metallofullerene Sc3C2@C80 with a fluorescent nanohoop of tetra-benzothiadiazole-based [12]cycloparaphenylene (TB[12]CPP), and its spin and fluorescence properties were comprehensively investigated. Temperature-dependent electron paramagnetic resonance (EPR) spectroscopy and fluorescence analyses were conducted. Synchronous changes in the EPR signals and fluorescence peaks were discovered in the temperature range of 170–290 K. Based on nuclear magnetic resonance observations and theoretical calculations, a temperature-dependent host—guest interaction between Sc3C2@C80 and a nanohoop was demonstrated, which explained the synchronous changes in the EPR signals and fluorescence peaks for Sc3C2@C80⊂TB[12]CPP. The application of Sc3C2@C80 as a molecular spin system to probe the host—guest interaction was also evaluated. These results show that the supramolecular assembly can be used to design advanced spin systems coupled with optical and magnetic behaviors based on paramagnetic and luminescent molecules. [ABSTRACT FROM AUTHOR]

Molecular machines have attracted extensive attention due to their fancy concept and their potential to influence the science and technology. The dynamic motion of encapsulated metallic clusters is a distinctive character for endohedral metallofullerenes. For the development of molecular rotors based on metallofullerenes, the most challenging issue is how to control the motion of untouchable metallic cluster inside fullerene cage. In this work, we report a molecular brake hoop for the motion of metal atoms inside fullerene cage. A cycloparaphenylene of [12]CPP was employed to hoop the metallofullerene and produce two supramolecular complexes of Sc3N@C80⊂[12]CPP and Sc2C2@C82⊂[12]CPP. Moreover, the temperature-dependent 45Sc nuclear magnetic resonance spectroscopy (NMR) was employed to detect the motion of internal Sc3N and Sc2C2 clusters. 45Sc NMR results reveal that the [12]CPP can slow down the rotation of internal metallic cluster through host-guest interaction, and thus the [12]CPP can be considered as a molecular brake hoop for the internal metal motion of metallofullerenes. Furthermore, by means of this molecular brake hoop, the motion of metal atoms inside fullerene cage have expanded range of velocity. In addition, theoretical calculations on Sc3N@C80⊂[12]CPP were executed to illustrate the molecular orientation as well as internal Sc3N rotation. This study would promote the research of endohedral metallofullerene as a molecular rotor. [ABSTRACT FROM AUTHOR]

This report deals with the quantum-chemical evaluation of the energetics and thermodynamics of the simultaneous encapsulation of HF and H2O by the IPR (isolated pentagon rule) C70 fullerene cage, yielding H2O·HF@C70 species which were synthesized and characterized recently, thus further expanding the family of fullerene endohedrals with non-metallic encapsulates. The structures were optimized at the DFT (density functional theory) M06-2X/6-31++G** level. The encapsulation energetics were further refined by the advanced B2PLYPD/6-31++G** and B2PLYPD/6-311++G** methods. After enhancement of the B2PLYPD/6-311++G** encapsulation energy for the BSSE and steric corrections, the encapsulation energy gain was obtained, as 26 kcal/mol. The equilibrium encapsulation thermodynamics were described using the M06-2X/6-31++G** partition functions. The results correspond to our previous evaluations for the water dimer encapsulation by C84 cages.

Soot-containing terbium (Tb)-embedded fullerenes were prepared by evaporation of Tb4O7-doped graphite rods in an electric arc discharge chamber. After 1,2,4-trichlorobenzene extraction of the soot and rotary evaporation of the extract, a solid product was obtained and then dissolved into toluene by ultrasonication. Through a three-stage high-pressure liquid chromatographic (HPLC) process, Tb@C82 (I, II) isomers were isolated from the toluene solution of fullerenes and metallofullerenes. With the success of the growth of cocrystals of Tb@C82 (I, II) with Ni(OEP), the molecular structures of Tb@C82 (I) and Tb@C82 (II) were confirmed to be Tb@C2v(9)-C82 and Tb@Cs(6)-C82, respectively, based on crystallographic data from X-ray single-crystal diffraction. Moreover, it was found that Tb@C82 (I, II) isomers demonstrated different packing behaviors in their cocrystals with Ni(OEP). Tb@C2v(9)-C82 forms a 1:1 cocrystal with Ni(OEP), in which Tb@C2v(9)-C82 is aligned diagonally between the Ni(OEP) bilayers to form zigzag chains. In sharp contrast, Tb@Cs(6)-C82 forms a 2:2 cocrystal with Ni(OEP), in which Tb@Cs(6)-C82 forms a centrosymmetric dimer that is aligned linearly with Ni(OEP) pairs to form one-dimensional structures in the a–c lattice plane. In addition, the distance of a Ni atom in Ni(OEP) to the Cs(6)-C82 cage is much shorter than that to the C2v(9)-C82 one, indicative of a stronger π-π interaction between Ni(OEP) and the C82 carbon cage in the cocrystal of Tb@CS(6)-C82 and Ni(OEP). Density functional theory calculations reveal that the regionally selective dimerization of Tb@CS(6)-C82 is the result of a dominant unpaired spin existing on a particular C atom of the CS(6)-C82 cage.

The photoelectrochemical properties of three metallofullerene-[12]cycloparaphenylene ([12]CPP) supramolecular complexes of Sc3N@C78⊂[12]CPP, Sc3N@C80⊂[12]CPP, and Sc2C2@C82⊂[12]CPP were studied. It was revealed that the photocurrent responses of these supramolecular complexes show enhancement compared with those of pristine metallofullerenes, indicating the efficient photocurrent generation and promoted charge carrier transport caused by the supramolecular interaction. The results show that Sc2C2@C82 and Sc2C2@C82⊂[12]CPP have the strongest photocurrents. Then, by comparing the photocurrent intensities of the metallofullerene-biphenyl derivates mixture and the metallofullerene⊂[12]CPP complexes, it was demonstrated that the host–guest interaction is the key factor promoting photocurrent enhancement. At the same time, by observing the microscopic morphologies of pristine fullerenes and supramolecular complexes, it was found that the construction of supramolecules helps to improve the morphology of metallofullerenes on FTO glass. Additionally, their electrical conductivity in optoelectronic devices was tested, respectively, indicating that the construction of supramolecules facilitates the transport of charge carriers. This work discloses the potential application of metallofullerene supramolecular complexes as photodetector and photoelectronic materials. [ABSTRACT FROM AUTHOR]

Tubular fullerenes can be considered as end‐capped carbon nanotubes with accurate structure, which are promising nanocarbon materials for advanced single‐molecule electronic devices. Herein, we report the synthesis and characterization of a metallofullertube Ce2@D5(450)‐C100, which has a tubular C100 cage with a carbon nanotube segment and two fullerene end‐caps. As there are structure correlations between tubular Ce2@D5(450)‐C100 and spherical Ce2@Ih‐C80, their structure–property relationship has been compared by means of experimental and theoretical methods. Notably, single‐molecule conductance measurement determined that the conductivity of Ce2@D5(450)‐C100 was up to eight times larger than that of Ce2@Ih‐C80. Furthermore, supramolecular assembly of Ce2@D5(450)‐C100 and a [12]CPP nanohoop was investigated, and theoretical calculations revealed that metallofullertube Ce2@D5(450)‐C100 adopted a "standing" configuration in the cavity of [12]CPP. These results demonstrate the special nature of this kind of metallofullertube. [ABSTRACT FROM AUTHOR]

Under photoirradiation, Sc3N@Ih-C80 reacted readily with disilirane 1, silirane 4, and digermirane 7 to afford the corresponding 1:1 adducts, whereas Sc3N@D5h-C80 was recovered without producing those adducts. Based on these results, we described a novel method for the exclusive separation of Ih and D5h isomers of Sc3N@C80. The method includes three procedures: selective derivatization of Sc3N@Ih-C80 using 1, 4, and 7, facile HPLC separation of pristine Sc3N@D5h-C80 and Sc3N@Ih-C80 derivatives, and thermolysis of Sc3N@Ih-C80 derivatives to collect pristine Sc3N@Ih-C80. In addition, laser flash photolysis experiments were conducted to elucidate the reaction mechanism. Decay of the transient absorption of 3Sc3N@Ih-C80 * was observed to be enhanced in the presence of 1, indicating the quenching process. When Sc3N@D5h-C80 was used, the transient absorption was much less intensive. Therefore, the quenching of 3Sc3N@D5h-C80 * by 1 could not be confirmed. Furthermore, we applied time-dependent density functional theory (TD-DFT) calculations of the photoexcited states of Sc3N@C80 to obtain insights into the reaction mechanism. [ABSTRACT FROM AUTHOR]

Paramagnetic endohedral metallofullerenes with well protected unpaired spin have potential applications in molecular-scale qubit processing and magnetoreception system. In this study, a paramagnetic metallofullerene Sc3C2@C80 dimer with covalently bonded two spin centers was synthesized. Electron paramagnetic resonance (EPR) results further revealed the varied spin-nuclei couplings and paramagnetic property for Sc3C2@C80 dimer. Briefly, the Sc3C2@C80 dimer in toluene solution shows EPR hyperfine splittings originating from the spin-Sc couplings. However, the Sc3C2@C80 dimer in solid state shows the disappearance of hyperfine structure and a single EPR signal caused by its two-spin-center structure. The transformation of EPR signals can be further finely modulated by controlling the dynamic motion of Sc3C2@C80 dimer in chloronaphthalene. The Sc3C2@C80 dimer with two spin centers possesses varied paramagnetic properties, demonstrating its potential as new magnetic material. [ABSTRACT FROM AUTHOR]

The photoelectrochemical properties of three metallofullerene-[12]cycloparaphenylene ([12]CPP) supramolecular complexes of Sc3N@C78⊂[12]CPP, Sc3N@C80⊂[12]CPP, and Sc2C2@C82⊂[12]CPP were studied. It was revealed that the photocurrent responses of these supramolecular complexes show enhancement compared with those of pristine metallofullerenes, indicating the efficient photocurrent generation and promoted charge carrier transport caused by the supramolecular interaction. The results show that Sc2C2@C82 and Sc2C2@C82⊂[12]CPP have the strongest photocurrents. Then, by comparing the photocurrent intensities of the metallofullerene-biphenyl derivates mixture and the metallofullerene⊂[12]CPP complexes, it was demonstrated that the host–guest interaction is the key factor promoting photocurrent enhancement. At the same time, by observing the microscopic morphologies of pristine fullerenes and supramolecular complexes, it was found that the construction of supramolecules helps to improve the morphology of metallofullerenes on FTO glass. Additionally, their electrical conductivity in optoelectronic devices was tested, respectively, indicating that the construction of supramolecules facilitates the transport of charge carriers. This work discloses the potential application of metallofullerene supramolecular complexes as photodetector and photoelectronic materials.

The enclosed space within fullerene molecules, capable of trapping metal clusters, offers an opportunity to investigate the behavior of metal atoms in a highly confined sub-nanometer environment. However, the studies on trimetallofullerenes M 3 @C 80 have been very limited due to their difficult obtainability. In this paper, we present a new method for obtaining a tri-metallofullerene Er 3 @C 80 through exohedral modification of the fullerene cage. Our findings reveal that Er 3 @C 80 exhibits a radical character and can react with the dichlorobenzene radical to generate a stable derivative Er 3 @C 80 PhCl 2 . Theoretical calculations demonstrate the presence of a three-center two-electron metal-metal bond in the center of the fullerene cage. This bond serves to counterbalance the Coulomb repulsion between the Er ions. Consequently, both exohedral derivatization and endohedral three-center bonding contribute to the substantial stability of Er 3 @C 80 PhCl 2 . Furthermore, molecular dynamics simulations indicate that the Er 3 cluster within the molecule possesses a rigid triangle structure. The availability of M 3 @C 80 derivatives opens avenues for future investigations into interactions among metal atoms, such as magnetic coupling, within fullerene cages., (© 2024 Wiley-VCH GmbH.)

A novel radical reaction of monometallofullerene Y@C2v(9)-C82 with N-arylbezamidine (1) is successfully conducted through catalysis with silver carbonate. The high-performance liquid chromatographic and mass spectrum results demonstrate that the reaction is highly regioselective to afford only one monoadduct (2) with an imidazoline group added on C82 cage, and computations through density functional theory reveal the addition group is attached to a specific [5, 6]-bond (C20-C76) near the Y atom. Furthermore, the analysis of prymidalization angle of the carbon atoms demonstrates the geometry of carbon cage is in favor of the regioselective formation of isomer (20, 76).

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Encapsulating one to three metal atoms or a metallic cluster inside fullerene cages affords endohedral metallofullerenes (EMFs) classified as mono‐, di‐, tri‐, and cluster‐EMFs, respectively. Although the coexistence of various EMF species in soot is common for rare‐earth metals, we herein report that europium tends to prefer the formation of mono‐EMFs. Mass spectroscopy reveals that mono‐EMFs (Eu@C2n) prevail in the Eu‐containing soot. Theoretical calculations demonstrate that the encapsulation energy of the endohedral metal accounts for the selective formation of mono‐EMFs and rationalize similar observations for EMFs containing other metals like Ca, Sr, Ba, or Yb. Consistently, all isolated Eu‐EMFs are mono‐EMFs, including Eu@D3h(1)‐C74, Eu@C2v(19138)‐C76, Eu@C2v(3)‐C78, Eu@C2v(3)‐C80, and Eu@D3d(19)‐C84, which are identified by crystallography. Remarkably, Eu@C2v(19138)‐C76 represents the first Eu‐containing EMF with a cage that violates the isolated‐pentagon‐rule, and Eu@C2v(3)‐C78 is the first C78‐based EMF stabilized by merely one metal atom. [ABSTRACT FROM AUTHOR]

Abstract A new class of single‐molecule magnets (SMMs) based on Dy‐oxide clusterfullerenes is synthesized. Three isomers of Dy2O@C82 with Cs(6), C3v(8), and C2v(9) cage symmetries are characterized by single‐crystal X‐ray diffraction, which shows that the endohedral Dy−(µ2‐O)−Dy cluster has bent shape with very short Dy−O bonds. Dy2O@C82 isomers show SMM behavior with broad magnetic hysteresis, but the temperature and magnetization relaxation depend strongly on the fullerene cage. The short Dy−O distances and the large negative charge of the oxide ion in Dy2O@C82 result in the very strong magnetic anisotropy of Dy ions. Their magnetic moments are aligned along the Dy−O bonds and are antiferromagnetically (AFM) coupled. At low temperatures, relaxation of magnetization in Dy2O@C82 proceeds via the ferromagnetically (FM)‐coupled excited state, giving Arrhenius behavior with the effective barriers equal to the AFM‐FM energy difference. The AFM‐FM energy differences of 5.4–12.9 cm−1 in Dy2O@C82 are considerably larger than in SMMs with {Dy2O2} bridges, and the Dy∙∙∙Dy exchange coupling in Dy2O@C82 is the strongest among all dinuclear Dy SMMs with diamagnetic bridges. Dy‐oxide clusterfullerenes provide a playground for the further tuning of molecular magnetism via variation of the size and shape of the fullerene cage.

Synthesis of molecular compounds with metal-metal bonds between 4f elements is recognized as one of the fascinating milestones in lanthanide metallochemistry. The main focus of such studies is on heavy lanthanides due to the interest in their magnetism, while bonding between light lanthanides remains unexplored. In this work, the Nd─Nd bonding in Nd-dimetallofullerenes as a case study of metal-metal bonding between early lanthanides is demonstrated. Combined experimental and computational study proves that pristine Nd 2 @C 80 has an open shell structure with a single electron occupying the Nd─Nd bonding orbital. Nd 2 @C 80 is stabilized by a one-electron reduction and further by the electrophilic CF 3 addition to [Nd 2 @C 80 ] - . Single-crystal X-ray diffraction reveals the formation of two Nd 2 @C 80 (CF 3 ) isomers with D 5h -C 80 and I h -C 80 carbon cages, both featuring a single-electron Nd─Nd bond with the length of 3.78-3.79 Å. The mutual influence of the exohedral CF 3 group and endohedral metal dimer in determining the molecular structure of the adducts is analyzed. Unlike Tb or Dy analogs, which are strong single-molecule magnets with high blocking temperature of magnetization, the slow relaxation of magnetization in Nd 2 @I h -C 80 (CF 3 ) is detectable via out-of-phase magnetic susceptibility only below 3 K and in the presence of magnetic field., (© 2023 The Authors. Advanced Science published by Wiley-VCH GmbH.)

Endohedral metallofullerenes have excellent redox properties, which can be used to vary their reactivity to certain classes of molecules, such as alkyl halides. In this study, the thermal reaction of the La@ C 2 v -C 82 anion with benzyl bromide derivatives 1 at 110 °C afforded single-bonded adducts 2 - 5 with high regioselectivity. The products were characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and visible-near infrared spectroscopy. The reaction of La@ C 2 v -C 82 with alkyl halides using the same conditions showed no consumption of La@ C 2 v -C 82 , indicating that the reactivity of La@ C 2 v -C 82 toward alkyl halides was effectively increased by one-electron reduction. Single-crystal X-ray diffraction analysis of the single-bonded adduct 3a revealed the addition site of the p -methoxybenzyl group on La@ C 2 v -C 82 . Theoretical calculations indicated that the addition site carbons in neutral La@ C 2 v -C 82 have high spin density, whereas those in the La@ C 2 v -C 82 anion do not have high charge densities. Thus, the reaction is believed to occur via electron transfer, followed by the radical coupling of La@ C 2 v -C 82 and benzyl radicals, rather than by bimolecular nucleophilic substitution reaction of La@ C 2 v -C 82 anion with 1 ., (Copyright © 2023, Maeda et al.)

Towards investigation on the application of metallofullerene in the removal of mustard gas, a fullerene C20 has been considered for substitutional doping by three of transition metals (Ti, Fe, and Ni). The resulted metallofullerenes (C19Ti, C19Fe, and C19Ni) were considered for the interaction of mustard gas in its surface by using DFT calculations in B3LYP-D3/631G (d,p) level of theory. We used NBO and frontier molecular orbital (FMO) techniques to track the change in the electronic structure of metallofullerenes upon mustard gas adsorption. During adsorption of mustard gas, the direction of charge transfer is from mustard to clusters which points towards p-type conduction property of metallofullerenes. Our results reveal that the metallofullerene may be an ideal candidate for the adsorption of mustard gas with adsorption energies in the range of − 96 to − 102 kJ/mol. [ABSTRACT FROM AUTHOR]

Magneto-luminescent molecules have significant applications in data storage and quantum computing. However, design of these bi-functional molecules coupled with magnetic behavior and photoluminescence is still challenging. In this work, we report a metallofullerene DyErScN@Ih-C80 exhibiting single-molecule magnet (SMM) behavior and near-infrared emission. For DyErScN@Ih-C80, two functional lanthanide metal ions of Dy3+ (SMM function) and Er3+ (luminescent function) are integrated inside a fullerene cage using a trimetallic nitride template, and its structure has been unambiguously characterized by single-crystal X-ray diffraction. Magnetic measurements revealed that DyErScN@Ih-C80 behaves as a SMM with a blocking temperature up to 9 K resulting from the intramolecular magnetic interaction between Dy3+ and Er3+ ions. Moreover, DyErScN@Ih-C80 exhibits temperature-dependent near-infrared emission around 1.5 μm with multiple splitting peaks from Er3+, which arises from the influence of Dy3+ ion. This study provides a new strategy to synthesize new magneto-luminescent molecule materials. [ABSTRACT FROM AUTHOR]

Soot containing Tb2C90 was synthesized in a modified Krätschmer-Huffman generator by vaporizing the composite graphite rods containing a mixture of Tb4O7 and graphite powder at an atmosphere of 300 torr He. The as-produced soot was collected and refluxed in 1,2,4-trichlorobenzene (TCB) for 12 h. After filtration and distillation to remove TCB, the product was immediately dissolved in toluene, and then subjected to HPLC separation to obtain the two individual isomers of Tb2C90 (I, II), which were confirmed by matrix-assisted laser desorption time-of-flight mass spectrometry and analytical HPLC. According to its UV-Vis-NIR absorption spectrum, the molecular structure of Tb2C90 (II) was estimated to be Tb2C2@Cs(hept)-C88, in which four electrons are transferred from endohedral Tb2C2 carbide cluster to the Cs(hept)-C88 carbon cage. The electrochemical properties of Tb2C90 (I, II) isomers was investigated by cyclic voltammetry. It is found that the first reduction of Tb2C90 (II) is close to that of Tb2C90 (I), whereas its first oxidation potential is larger than that of Tb2C90 (I). Hence, is a better electron acceptor than Tb2C90 (I). Moreover, the electrochemical potential gap of Tb2C90 (II) is larger than that of Tb2C90 (I), which is correlated with the thermodynamic stability and relative abundance of the two isolated Tb2C90 isomers. Through comparative study of Tb2C2@Cs(hept)-C88 and Sc2C2@Cs(hept)-C88, it is concluded that the endohedral dimetallo-carbide cluster has greater effect on the oxidation properties than reduction properties of dimetallo-carbide clusterfullerenes. [ABSTRACT FROM AUTHOR]

Density functional theory calculations have been performed for structures, electronic and non-linear optical properties of C 20 fullerene and transition metals (chromium, nickel, and titanium) doped fullerene. The NBO charge distribution analysis reveals that doping with transition metal alters the charge distribution of C 20 fullerene. The changes are more pronounced on doping with Ti followed by Cr and Ni, respectively. The dipole moment for TiC 19 is higher than Cr C 19 and NiC 19 and it decreases monotonically across the period. The first hyperpolarizability of C 20 fullerene is remarkably increased by transition metal doping. The first hyperpolarizability of Ti C 19 is 2.5 × 10 3 , three orders of magnitude higher than that of pure fullerene. The density of states (DOS), and frontier molecular orbital analyses confirm significant orbital hybridization upon metal doping in C 20 fullerene, which suggest potential application of new clusters which may be important for the future development of fullerene-based nanodevices. [ABSTRACT FROM AUTHOR]

With their intriguing structures and properties, metallofullerenols have attracted considerable attention in biological and medical applications. Due to the increasing biomedical interest, effective detection methods are important to monitor and control metallofullerenols. However, the detection of metallofullerenols becomes very difficult after polyhydroxylated modification due to the lack of detectable features. Antibody-based immunoassay methods have been important tools for detection and will better meet the needs of analysis of metallofullerenols. Thus, the antigenicity of metallofullerenol has been studied for the first time. In this study, no immune response was detected when metallofullerenol Gd@C(OH) was used as immunogen. However, the polyclonal antibody against metallofullerenol was produced using metallofullerenol-KLH (keyhole limpet hemocyanin) as immunogen, indicating that metallofullerenol can act as hapten. The specificity of the obtained antibody was investigated. It has been found that the hydroxyl groups on the surface of the carbon cage, the encapsulated metal, and the size and shape of the carbon cage did not affect the recognition specificity of the antibody. Based on the obtained antibody, an indirect competitive enzyme immunoassay was developed for the determination of metallofullerenol with detection limits of 18 ng/mL in PBS. This enzyme immunoassay method was successfully used to detect metallofullerenol in serum. This work can provide an innovative way to determine metallofullerenols. [ABSTRACT FROM AUTHOR]

The larger and less-studied metallic nitride fullerene, Gd 3 N@C 88 , is chemically isolated by manipulating its inertness to 3-aminopropanol in a xylene solvent system. An advantage of aminopropanol–xylene is the liquid phase of all species. This homogeneous nature mitigates sample loss that accompanies heterogeneous media, such as aminosilica. Respectful to green chemistry, our chemical purification approach eliminates chlorinated solvents. The inexpensive reagents require no preliminary synthesis prior to use. In stage one, fullerene and metallofullerene contaminants are easily transferred into a hydrophilic layer upon attaching water-soluble groups to the cage surface. In stage two, Gd 3 N@C 88 is selectively precipitated with ZnCl 2 and de-complexed to yield a sample of 84% purity. A single HPLC injection provides 99% Gd 3 N@C 88 . [ABSTRACT FROM AUTHOR]

Abstract: Aqueous dispersions of an unmodified (pristine) (AFD) nY@C82 (symmetry C2v) endofullerene were produced with a nearly 100% yield relative to the initial toluene solution of the endofullerene. To the best of our knowledge, this is the first report of this kind of endofullerene aqueous dispersions. The solvent‐exchange ultrasound‐assisted procedure requires no modification of the endofullerene surface or addition of any stabilizing agents into the aqueous phase. The procedure is applicable to any endohedral metallofullerene aqueous dispersions suitable for biomedical applications. The resulting dispersions are stable for at least 6 months. For the produced aqueous dispersions of Y@C82, the zeta potential of ca. –42 mV shows good stability; the average diameter of clusters was as small as ca. 120 nm. Techniques for purification and purity control of nY@C82 and of the intermediate toluene solution of Y@C82 were developed. The residual quantity of organic compounds was less than 1 ppb after the purification. Based on ICP–AES, headspace GC–MS, and MALDI–TOF, a procedure to assess endofullerene concentrations in the aqueous phase was proposed. [ABSTRACT FROM AUTHOR]