Endohedral lanthanide metallofullerene molecules exhibit various paramagnetic properties. In this study, we present a magnetoreception probe that can detect the magnetic properties of an endohedral metallofullerene via spin-paramagnet interaction between a nitroxide radical and Dy3N@C80. A cycloaddition reaction on the outer cage of Dy3N@C80 was employed to obtain two regioisomers linked with the nitroxide radical; the resultant adduct exhibits site-dependent signal intensity in the ESR spectra. This Dy3N@C80-nitroxide radical adduct has potential applications as a molecular compass with position-sensitive magnetoreception ability.

The electron spin properties of endohedral metallofullerene molecules have broad potential applications in quantum information and magnetic induction systems due to the high stability and sensitivity. Herein, we synthesized a series of Y3N@C2n (n = 40–44) molecules and studied the hyperfine structures of their anion radicals via ESR measurements and DFT calculations. N-Hyperfine couplings were clearly observed in the ESR spectra of charged Y3N@C80 and Y3N@C86 anion radicals, which are not found in the other metallofullerenes. The ESR results revealed size-dependent spin distributions and hyperfine structures, which are sensitive to subtle changes in the carbon cage and the configuration of the yttrium nitride cluster. BOMD cluster trajectories simulations indicated that the Y3N cluster almost rotates freely in neutral Y3N@C80 but there is a certain degree of limitation in the Y3N@C80 anion.

A new water-soluble gadolinium metallofullerenol was prepared through a solid–liquid reaction. It was characterized to have an enhanced effective magnetic moment, and improved T1-weighted relaxivity and magnetic resonance imaging performance in the liver. This material prepared by a facile method has wide application as a contrast agent and biological medicine.

The paramagnetic metallofullerenes wrapped lanthanide metals have many special properties and potential applications, especially as a single-molecule magnet. Herein, we report a spin probe of nitroxide radical for the magnetic dysprosium metallofullerenes. The nitroxide radical was connected to dysprosium metallofullerene though a cycloaddition reaction. Two kinds of dysprosium metallofullerene, DySc2N@C80 and Dy2ScN@C80 with different characters of molecule magnet, were selected. By means of analyzing electronic spin resonance spectra of nitroxide radical, the spin-paramagnet interactions between nitroxide and dysprosium metallofullerenes were investigated.

Paramagnetic endohedral fullerenes are ideal candidates for quantum information processing and high-density data storage due to their protected spins with particularly high stability. Herein, we report a solid spin system based on a paramagnetic metallofullerene Y2@C79N through incarcerating it into the cage-shaped pores of a metal–organic framework (MOF-177). In this kind of guest and host complex, the Y2@C79N molecules inside the pores of MOF crystal show axisymmetric paramagnetic property. It was found that the pores of MOF-177 crystal play an important role in dispersing the Y2@C79N molecules as well as in steering their electron spin. The group of arranged Y2@C79N molecules and their electron spins in MOF crystals are potential quantum bits for quantum information science and data storage. Moreover, this kind of solid spin system can be used as a probe for nanoscale nuclear magnetic resonance or for motion imaging of a single biomolecule.

A kind of Gd@C82 salt, Gd@C82/TBPA, was prepared through chemical oxidation. The Gd@C82/TBPA salt was characterized as being paramagnetic with an effective magnetic moment of 9.68μB. The Gd@C82/TBPA salt dissolves in many organic solvents and its high solubility will make it more applicable for use as a magnetic material.

The internal clusters in metallofullerenes usually exhibit certain motion that is potentially usable in molecular gyroscopes and nano-machines. Based on 45Sc NMR, the motion of the scandium nitride cluster within the C80 cage was investigated via varying the temperature and modifying the cage, and by changing the cluster size.

A hydrogen-containing endohedral metallofullerene, Sc4C2H@Ih-C80, was synthesized and its paramagnetism was measured by the low-temperature EPR spectrometry with a broad EPR signal. The electron-spin excitation by implanting the H-atom would be a new method for preparation of stable paramagnetic metallofullerenes.

A metallofullerene radical Y2@C81N was synthesized and characterized by ESR spectroscopy and ab initio calculations. It was revealed that the molecule adopts an unique azafullerene C81N cage derived from C82-C2v(9), and two yttrium ions are entrapped to form the endohedral structure. The unpaired electron of Y2@C81N radical was calculated to mainly localize on the Y2 dimer, leading to large hyperfine coupling constants of 75.7 and 69.8 G for the two yttrium nuclei.

We present a metal carbide clusterfullerene Sc2C2@Cs(10528)–C72, whose structure has been baffling for many years. A motional endohedral Sc2C2 cluster, special molecule geometry and electronic structure were found in Sc2C2@Cs(10528)–C72. The paramagnetic Sc2C2@Cs–C72 anion radical was successfully prepared by a chemical reduction method and hyperfine couplings in the ESR spectrum were observed.

A paramagnetic Sc3NC@C80 anion radical was obtained by chemical reduction. ESR spectrometry and theoretical calculations disclosed that the core NC moiety takes possession of the unpaired electron and stabilizes the paramagnetic species. It is the first time a paramagnetic metal cyanide metallofullerene has been obtained.

A fullerene derivative linked with an adamantane cage, [6,6]-phenyl-C61-butyric acid 1-adamantane methyl ester (PC61BAd), has been designed and synthesized. Systematic investigations on its organic field effect performance, photovoltaic properties, and corresponding thermal stability have been made. In OFET device, the electron mobility (μe) of PC61BAd was found to reach a value as high as 0.01 cm2/V·s with a high on-off (Ion/Ioff) ratio of 4.9 × 106 that is useful for logic device applications. In the organic photovoltaic devices of P3HT:PC61BAd, the power conversion efficiency (PCE) was found to reach 3.31 % in the optimized device. More importantly, the active layer of P3HT:PC61BAd was found to exhibit superior thermal stability over that of P3HT:PC61BM. After heating at 150 °C for 20 h, the P3HT:PC61BAd device still showed a PCE of 2.44 %, demonstrating the applicability of PC61BAd as an acceptor material for the preparation of thermally stable organic solar cells. X-ray diffraction and atomic force microscopy were employed to probe the structure and morphology of PC61BAd and to rationalize its performance as an organic electronic material.Keywords: adamantane; field effect transistor; fullerene derivative; organic photovoltaics; thermal stability;

Endohedral metallofullerene species with controllable electron spin have attracted increasing attention along with their potential application in quantum information processing. In this paper, we report the electron spin manipulation via encage cluster through comparative studies on the anion radicals of metallofullerene Y2@C82-Cs, Y2C2@C82-Cs, and Sc2C2@C82-Cs. Although these three radical species have the same parent fullerene cage, we found that the unpaired spin characteristics as well as metal-spin couplings of them can be greatly affected by endohedral clusters. Furthermore, based on theoretical calculations, it was revealed that the encaged clusters can affect the electronic population of pristine endohedral metallofullerenes and eventually manipulate the spin distribution of their corresponding anion radicals. Our findings are referential to the spin coherence in information processing due to the variable paramagnetism of these metallofullerene radicals.Keywords: anion radical; carbide cluster; electron spin; metallofullerene; molecular orbitals;

Highly impressionable electron spin was found in endohedral azafullerene Y2@C79N at low temperature or upon exohedral chemical modification. These external stimulations can be employed to manipulate the spin-active Y2@C79N and can further be used in quantum processes for promising information-carrying spin systems and molecular devices.

The bis-adducts of Sc3C2@C80 fulleropyrrolidines were prepared and isolated. ESR study showed that these bis-addition fulleropyrrolidines have varied paramagnetism resulting from diverse reaction sites for the second pyrrolidine addend.

A new metallofullerene Y3N@C78-C2 was synthesized and characterized. It was shown that Y3N@C78 has an unconventional C78-C2 cage with two pairs of fused pentagons closely bonded with two yttrium atoms. DFT calculations showed that the size of the ionic radii of the metals forming the caged cluster plays an important role in the non-isolated-pentagon-rule-feature of the C78 cage.

Following the first isolation of Sc3NC@C80, a second member of this family of endohedral metallofullerenes, Sc3NC@C78, was prepared by an arc-discharging method. Experimental and theoretical studies demonstrated that the Sc3NC@C78 has a C78-C2 cage with two pairs of adjacent pentagons, which is different from the IPR-satisfying Sc3N@C78-D3h. It was revealed that the size of C78-D3h is appropriate for the Sc3N cluster, but not large enough for encaging the large planar species Sc3NC. Theoretical calculations were preformed on Sc3NC@C78-C2 and Sc3NC@C78-D3h. The results show that Sc3NC would bear a strong depression inside the C78-D3h fullerene cage due to the limited internal space of C78-D3h; on the contrary, C78-C2 has two pairs of adjacent pentagons that induce a large curvature in these sites to form an oblate ellipsoid structure. Thus, it is more favorable to encapsulate the planar species Sc3NC. Ab initio calculations were also performed to further disclose the electronic and electrochemical properties of Sc3NC@C78-C2. It was revealed that the molecule has an electronic structure of (Sc3+)3(NC)3–@C786–, in which the inner species NC has an unprecedented (NC)3– trianion charging status similar to that in the recently reported Sc3NC@C80-Ih.

Endohedral lanthanide metallofullerene molecules exhibit various paramagnetic properties. In this study, we present a magnetoreception probe that can detect the magnetic properties of an endohedral metallofullerene via spin-paramagnet interaction between a nitroxide radical and Dy3N@C80. A cycloaddition reaction on the outer cage of Dy3N@C80 was employed to obtain two regioisomers linked with the nitroxide radical; the resultant adduct exhibits site-dependent signal intensity in the ESR spectra. This Dy3N@C80-nitroxide radical adduct has potential applications as a molecular compass with position-sensitive magnetoreception ability.

A new Sc3(C2)(CN)@Ih-C80 metallofullerene encaging a scandium carbide/cyanide alloyed cluster was prepared and investigated. Sc3(C2)(CN)@Ih-C80 was synthesized by the arc-discharging method and isolated by HPLC. Its experimental 13C NMR spectrum with two signals clearly confirms an icosahedral C80 cage, and theoretically calculated 13C NMR peaks agree well with the experimental results. Further, theoretical calculations disclosed that the endohedral μ3-C2 and μ3-CN moieties are situated on each side of the triangular shaped Sc3 unit to form a scandium carbide/cyanide alloyed cluster. Kohn–Sham molecular orbitals reveals the electronic structure of (Sc3+)3(C2)2−(CN)−@C806−, in which two anions, μ3-C22− and μ3-(CN)−, construct and stabilize this special molecule together. The FTIR and Raman spectra of Sc3(C2)(CN)@Ih-C80 were analyzed by comparison of the experimental and calculated results to further confirm its structure and to uncover cluster-based vibrational modes.

The internal clusters in metallofullerenes usually exhibit certain motion that is potentially usable in molecular gyroscopes and nano-machines. Based on 45Sc NMR, the motion of the scandium nitride cluster within the C80 cage was investigated via varying the temperature and modifying the cage, and by changing the cluster size.

The bis-adducts of Sc3C2@C80 fulleropyrrolidines were prepared and isolated. ESR study showed that these bis-addition fulleropyrrolidines have varied paramagnetism resulting from diverse reaction sites for the second pyrrolidine addend.

A metallofullerene radical Y2@C81N was synthesized and characterized by ESR spectroscopy and ab initio calculations. It was revealed that the molecule adopts an unique azafullerene C81N cage derived from C82-C2v(9), and two yttrium ions are entrapped to form the endohedral structure. The unpaired electron of Y2@C81N radical was calculated to mainly localize on the Y2 dimer, leading to large hyperfine coupling constants of 75.7 and 69.8 G for the two yttrium nuclei.

A kind of Gd@C82 salt, Gd@C82/TBPA, was prepared through chemical oxidation. The Gd@C82/TBPA salt was characterized as being paramagnetic with an effective magnetic moment of 9.68μB. The Gd@C82/TBPA salt dissolves in many organic solvents and its high solubility will make it more applicable for use as a magnetic material.

A new water-soluble gadolinium metallofullerenol was prepared through a solid–liquid reaction. It was characterized to have an enhanced effective magnetic moment, and improved T1-weighted relaxivity and magnetic resonance imaging performance in the liver. This material prepared by a facile method has wide application as a contrast agent and biological medicine.

Highly impressionable electron spin was found in endohedral azafullerene Y2@C79N at low temperature or upon exohedral chemical modification. These external stimulations can be employed to manipulate the spin-active Y2@C79N and can further be used in quantum processes for promising information-carrying spin systems and molecular devices.

A paramagnetic Sc3NC@C80 anion radical was obtained by chemical reduction. ESR spectrometry and theoretical calculations disclosed that the core NC moiety takes possession of the unpaired electron and stabilizes the paramagnetic species. It is the first time a paramagnetic metal cyanide metallofullerene has been obtained.

A hydrogen-containing endohedral metallofullerene, Sc4C2H@Ih-C80, was synthesized and its paramagnetism was measured by the low-temperature EPR spectrometry with a broad EPR signal. The electron-spin excitation by implanting the H-atom would be a new method for preparation of stable paramagnetic metallofullerenes.