Are U-U Bonds Inside Fullerenes Really Unwilling Bonds?

Previous characterizations of diactinide endohedral metallofullerenes (EMFs) Th2@C80 and U2@C80 have shown that although the two Th3+ ions form a strong covalent bond within the carbon cage, the interaction between the U3+ ions is weaker and described as an "unwilling" bond. To evaluate the feasibility of covalent U-U bonds, which are neglected in classical actinide chemistry, we have first investigated the formation of smaller diuranium EMFs by laser ablation using mass spectrometric detection of dimetallic U2@C2n species with 2n ≥ 50. DFT, CASPT2 calculations, and MD simulations for several fullerenes of different sizes and symmetries showed that thanks to the formation of strong U(5f3)-U(5f3) triple bonds, two U3+ ions can be incarcerated inside the fullerene. The formation of U-U bonds competes with U-cage interactions that tend to separate the U ions, hindering the observation of short U-U distances in the crystalline structures of diuranium endofullerenes as in U2@C80. Smaller cages like C60 exhibit the two interactions, and a strong triple U-U bond with an effective bond order higher than 2 is observed. Although 5f-5f interactions are responsible for the covalent interactions at distances close to 2.5 Å, overlap between 7s6d orbitals is still detected above 4 Å. In general, metal ions within fullerenes should be regarded as templates in cage formation, not as statistically confined units that have little chance of being observed.

Unexpected Formation of Metallofulleroids from Multicomponent Reactions, with Crystallographic and Computational Studies of the Cluster Motion.

New multicomponent reactions involving an isocyanide, terminal or internal alkynes, and endohedral metallofullerene (EMF) Lu3 N@C80 yield metallofulleroids which are characterized by mass-spectrometry, HPLC, and multiple 1D and 2D NMR techniques. Single crystal studies revealed one ketenimine metallofulleroid has ordered Lu3 N cluster which is unusual for EMF monoadducts. Computational analysis, based on crystallographic data, confirm that the endohedral cluster motion is controlled by the position of the exohedral organic appendants. Our findings provide a new functionalization reaction for EMFs, and a potential facile approach to freeze the endohedral cluster motion at relatively high temperatures.

A New Class of Molecular Electrocatalysts for Hydrogen Evolution: Catalytic Activity of M3N@C2n (2n = 68, 78, and 80) Fullerenes.

The electrocatalytic properties of some endohedral fullerenes for hydrogen evolution reactions (HER) were recently predicted by DFT calculations. Nonetheless, the experimental catalytic performance under realistic electrochemical environments of these 0D-nanomaterials have not been explored. Here, for the first time, we disclose the HER electrocatalytic behavior of seven M3N@2n (2n = 68, 78, and 80) fullerenes (Gd3N@Ih(7)-C80, Y3N@Ih(7)-C80, Lu3N@Ih(7)-C80, Sc3N@Ih(7)-C80, Sc3N@D5h(6)-C80, Sc3N@D3h(5)-C78, and Sc3N@D3(6140)-C68) using a combination of experimental and theoretical techniques. The non-IPR Sc3N@D3(6140)-C68 compound exhibited the best catalytic performance toward the generation of molecular hydrogen, exhibiting an onset potential of -38 mV vs RHE, a very high mass activity of 1.75 A·mg-1 at -0.4 V vs RHE, and an excellent electrochemical stability, retaining 96% of the initial current after 24 h. The superior performance was explained on the basis of the fused pentagon rings, which represent a new and promising HER catalytic motif.

Intervenciones para normalizar las actividades de la vida cotidiana en pacientes a los que se ha practicado una reciente ostomía / Interventions to normalize activities of daily living in patients who have had a recent ostomy

CASO: ejemplo mujer de mediana edad procedente de entorno rural a la que se ha practicado una ostomía digestiva definitiva. OBJETIVO: identificar intervenciones basadas en evidencias destinadas a fomentar la autonomía de la persona portadora de un estoma, garantizando su seguridad y motivación hacia el autocuidado. METODOLOGÍA: búsqueda de evidencias siguiendo el modelo PRAXIS. Recomendaciones de buena práctica: (a) colaborar conjuntamente con la paciente en el cuidado del estoma y manejo de dispositivos, (b) para satisfacer las necesidades básicas al descubierto, (c) educar en la prevención de complicaciones, (d) involucrar a la familia y entorno social, (e) apoyarse en el uso de tecnologías visuales y (f) apoyar el establecimiento de relaciones con pares para compartir experiencias. PRÁCTICAS DE AUTOCUIDADO: automanejo del estoma, compartir temores y experiencia con entorno social y grupos de apoyo, y utilización de recursos complementarios

CASE: example of a middle-aged woman from a rural environment who has undergone a definitive digestive ostomy. OBJECTIVE: to identify evidence-based interventions aimed at promoting the autonomy of the person with a stoma, guaranteeing their safety and motivation towards self-care. METHODOLOGY: search for evidence following the PRAXIS model. Good practice recommendations: (a) collaborate together with the patient in the care of the stoma and management of devices, (b) to satisfy the basic needs in the open, (c) educate in the prevention of complications, (d) involve the family and social environment, (e) rely on the use of visual technologies and (f) support the establishment of relationships with peers to share experiences. SELF-CARE PRACTICES: self-management of the stoma, sharing fears and experience with the social environment and support groups, and use of complementary resources

α-DTC70 Fullerene Performs Significantly Better than ß-DTC70 as Electron Transporting Material in Perovskite Solar Cells.

In this work, two new C70 isomers, α and ß bis(2-(thiophen-2-yl)ethyl)-C70-fullerene mono-adducts (DTC70), were synthesized, characterized and used as electron transporting materials (ETMs) in perovskite solar cells (PSCs). Our results show that the α isomer improves both the J sc and FF values of the devices, when compared to the results for the ß-isomer and to those for phenyl-C70-butyric acid methyl ester (PC71BM), used as control. Devices based on α-DTC70 achieved a power conversion efficiency (PCE) of 15.9%, which is higher than that observed with PC71BM (15.1%).

Formation of C2v-C72(11188)Cl4: A Particularly Stable Non-IPR Fullerene.

Halogenation has been one of the most used strategies to explore the reactivity of empty carbon cages. In particular, the higher reactivity of non-IPR fullerenes, i.e., those fullerenes that do not satisfy the isolated pentagon rule (IPR), has been used to functionalize and capture these less stable fullerenes. Here, we have explored the stability of the non-IPR isomer C72(11188) with C2v symmetry, which is topologically linked to the only IPR isomer of C70, as well as its reactivity to chlorination. DFT calculations and Car-Parrinello molecular dynamics simulations suggest that chlorination takes places initially in nonspecific sites, once carbon cages are formed. When the temperature in the arc reactor decreases sufficiently, Cl atoms are trapped on the fullerene surface, migrating from not-so-favored positions to reach the most favored sites in the pentalene. We have also discussed why cage C2v-C72(11188) is found to take four chlorines, whereas cage C1-C74(14049) is observed to capture 10 of them, even though these two fullerenes are closely related by a simple C2 insertion.