Facile Synthesis of Isomerically Pure Fullerenols and Formation of Spherical Aggregates from C60(OH)8

Structurally Defined Water-Soluble Metallofullerene Derivatives towards Biomedical Applications

Endohedral metallofullerenes (EMFs) are excellent carriers of rare-earth element (REE) ions in biomedical applications because they preclude the release of toxic metal ions. However, existing approaches to synthesize water-soluble EMF derivatives yield mixtures that inhibit precise drug design. Here we report the synthesis of metallobuckytrio (MBT), a three-buckyball system, as a modular platform to develop structurally defined water-soluble EMF derivatives with ligands by choice. Demonstrated with PEG ligands, the resulting water-soluble MBTs show superb biocompatibility. The Gd MBTs exhibit superior T1 relaxivity than typical Gd complexes, potentially superseding current clinical MRI contrast agents in both safety and efficiency. The Lu MBTs generated reactive oxygen species upon light irradiation, showing promise as photosensitizers. With their modular nature to incorporate other ligands, we anticipate the MBT platform to open new paths towards bio-specific REE drugs.

Interaction of polyhydroxy fullerenes with ferrihydrite: adsorption and aggregation

The rapid development of nanoscience and nanotechnology, with thousands types of nanomaterials being produced, will lead to various environmental impacts. Thus, understanding the behaviors and fate of these nanomaterials is essential. This study focused on the interaction between polyhydroxy fullerenes (PHF) and ferrihydrite (Fh), a widespread iron (oxyhydr)oxide nanomineral and geosorbent. Our results showed that PHF were effectively adsorbed by Fh. The adsorption isotherm fitted the D-R model well, with an adsorption capacity of 67.1mg/g. The adsorption mean free energy of 10.72kJ/mol suggested that PHF were chemisorbed on Fh. An increase in the solution pH and a decrease of the Fh surface zeta potential were observed after the adsorption of PHF on Fh; moreover, increasing initial solution pH led to a reduction of adsorption. The Fourier transform infrared spectra detected a red shift of C-O stretching from 1075 to 1062cm^-1 and a decrease of Fe-O bending, implying the interaction between PHF oxygenic functional groups and Fh surface hydroxyls. On the other hand, PHF affected the aggregation and reactivity of Fh by changing its surface physicochemical properties. Aggregation of PHF and Fh with individual particle sizes increasing from 2nm to larger than 5nm was measured by atomic force microscopy. The uniform distribution of C and Fe suggested that the aggregates of Fh were possibly bridged by PHF. Our results indicated that the interaction between PHF and Fh could evidently influence the migration of PHF, as well as the aggregation and reactivity of Fh.

Facilitating Electron Transportation in Perovskite Solar Cells via Water-Soluble Fullerenol Interlayers

TiO2 is widely used in perovskite solar cells (Pero-SCs), but its low electrical conductivity remains a drawback for application in electron transport layer (ETL). To overcome this problem, an easily accessible hydroxylated fullerene, fullerenol, was employed herein as ETL modified on ITO in n-i-p type (ITO as cathode) Pero-SCs for the first time. The results showed that the insertion of a single layer of fullerenol between perovskite and TiO2 dramatically facilitates the charge transportation and decreases the interfacial resistance. As a consequence, the device performance was greatly improved, and a higher power conversion efficiency of 14.69% was achieved, which is ∼17.5% enhancement compared with that (12.50%) of the control device without the fullerenol interlayer. This work provides a new candidate of interfacial engineering for facilitating the electron transportation in Pero-SCs.

Vesicular Nanostructure Formation by Self-Assembly of Anisotropic Penta-phenol-Substituted Fullerene in Water

A study on self-assembly of anisotropically substituted penta-aryl fullerenes in water has been reported. The penta-phenol-substituted amphiphilic fullerene derivative [C60Ph5(OH)5] exhibited self-assembled vesicular nanostructures in water under the experimental conditions. The size of the vesicles was observed to depend upon the kinetics of self-assembly and could be varied from ∼300 to ∼70 nm. Our mechanistic study indicated that the self-assembly of C60Ph5(OH)5 is driven by extensive intermolecular as well as water-mediated hydrogen bonding along with fullerene-fullerene hydrophobic interaction in water. The cumulative effect of these interactions is responsible for the stability of vesicular structures even on the removal of solvent. The substitution of phenol with anisole resulted in different packing and interaction of the fullerene derivative, as indicated in the molecular dynamics studies, thus resulting in different self-assembled nanostructures. The hollow vesicles were further encapsulated with a hydrophobic conjugated polymer and water-soluble dye as guest molecules. Such confinement of π-conjugated polymers in fullerene has significance in bulk heterojunction devices for efficient exciton diffusion.