A three-shell supramolecular complex enables the symmetry-mismatched chemo- and regioselective bis-functionalization of C60

Molecular Russian dolls (matryoshkas) have proven useful for testing the limits of preparative supramolecular chemistry but applications of these architectures to problems in other fields are elusive. Here we report a three-shell, matryoshka-like complex—in which C60 sits inside a cycloparaphenylene nanohoop, which in turn is encapsulated inside a self-assembled nanocapsule—that can be used to address a long-standing challenge in fullerene chemistry, namely the selective formation of a particular fullerene bis-adduct. Spectroscopic evidence indicates that the ternary complex is sufficiently stable in solution for the two outer shells to affect the addition chemistry of the fullerene guest. When the complex is subjected to Bingel cyclopropanation conditions, the exclusive formation of a single trans-3 fullerene bis-adduct was observed in a reaction that typically yields more than a dozen products. The selectivity facilitated by this matryoshka-like approach appears to be a general phenomenon and could be useful for applications where regioisomerically pure C60 bis-adducts have been shown to have superior properties compared with isomer mixtures.This work was supported by grants from MINECO-Spain (CTQ2016-77989-P and PID2019-104498GB-I00 to X.R., RTI2018-095622-B-100 to D.M. and I.I., and EUR2019-103824 to F.G.), Generalitat de Catalunya (2017SGR264 and a PhD grant to C.F.-E.) and the Severo Ochoa Center of Excellence Program (Catalan Institute of Nanoscience and Nanotechnology, grant SEV-2017-0706). X.R. is also grateful for ICREA-Acadèmia awards. M.v.D. is grateful for financial support from the Deutsche Forschungsgemeinschaft (project number 182849149-SFB953 ‘Synthetic Carbon Allotropes’), the Fonds der Chemischen Industrie (FCI), the University of Ulm and the Deutscher Akademischer Austauschdienst (PhD fellowship to O.B.). E.U. thanks Universitat de Girona for a PhD grant and we thank Serveis Tècnics de Recerca, Universitat de Girona for technical support.Peer reviewe

Synthesis and applications of large supramolecular nanocapsules: matryoshka-type masks, higher fullerene C84 purification and stabilization of metallic clusters and sub-nanoparticles

The development of supramolecular assemblies with big cavities is important to recognize specific guests or infer a chemo- or regioselective chemistry, in analogy to natural enzymes. The objective of this thesis was to design, synthesize and characterize new 3D supramolecular nanocapsules bearing large cavities to use them in different applications. Four new self-assembled nanocapsules were developed by self-assembly of Zn-TCPP with pTp or ppp (diarylalkyne- or terphenyl-based) macrocyclic ligands complexed with Pd or Cu, which lead to two different cavity sizes depending on the selected ligand. Then, host-guest studies for each nanocapsule were performed with different guests including fullerene-C60, the C60⸦[10]CPP complex, higher fullerenes and the azafullerene-(C59N)2. Furthermore, the synthesis of metallic nanoparticles was investigated in the presence of supramolecular nanocapsulesEl desenvolupament d'assemblatges supramoleculars amb cavitats grans és important per tal de reconèixer substrats específics o inferir un control en la quimio- o regioselectivitat d’un procés químic, en analogia als enzims naturals. L'objectiu d'aquesta tesi era dissenyar, sintetitzar i caracteritzar noves nanocàpsules supramoleculars 3D amb grans cavitats per utilitzar-les en diferents aplicacions. En concret quatre noves nanocapsules autoensamblades van ser desenvolupades. L’autoensamblatge de Zn-TCPP amb lligands macrocíclics pTp o ppp (basats en diarilalquí o terfenil, respectivament) complexats amb Pd o Cu va donar lloc a dos mides diferents de cavitat depenent del lligand. Seguidament, es van realitzar estudis d’afinitat per a cada nanocàpsula amb diferents substrats, incloent ful·lerè-C60, el complex C60⸦[10]CPP, ful·lerens d’ordre superior i l’azaful·lerè-(C59N)2. A més, s’ha investigat la síntesi de nanopartícules metàl·liques en presència de nanocàpsules supramolecularsPrograma de Doctorat en Químic

Synthesis of C60/[10]CPP‐Catenanes by Regioselective, Nanocapsule‐Templated Bingel Bis‐Addition

The addition of two unsymmetric malonate esters to the Buckminster fullerene C60 can lead to 22 spectroscopically distinguishable isomeric products and therefore represents a formidable synthesis challenge. In this work, we achieve 87 % selectivity for the formation of a single (in,out-trans-3) isomer by combining three approaches: (i) we use a starting material, in which the two malonates are covalently connected (tether approach); (ii) we form the strong supramolecular complex of C60 with the shape-persistent [10]CPP macrocycle (template approach) and (iii) we embed this complex further within a self-assembled nanocapsule (shadow mask approach). Variation of the spacer chain shed light on the limitations of the approach and the ring dynamics in the unusual [2]catenanes were studied in silico with atomistic resolution. This work significantly widens the scope of mechanically interlocked architectures comprising cycloparaphenylenes (CPP)

Supramolecular nanocapsules as two-fold stabilizers of outer-cavity sub-nanometric Ru NPs and inner-cavity ultra-small Ru clusters

International audienceThe synthesis of metallic nanoparticles (MNP) with high surface area and controlled shape is of paramount importance to increase their catalytic performance. The detailed growing process of NP is mostly unknown and understanding the specific steps would pave the way for a rational synthesis of the desired MNP. Here we take advantage of the stabilization properties exerted by the tetragonal prismatic supramolecular nanocapsule 8Á(BArF) 8 to develop a synthetic methodology for sub-nanometric RuNP (0.6-0.7 nm). The catalytic properties of these sub-nanometric nanoparticles were tested on the hydrogenation of styrene, obtaining excellent selectivity for the hydrogenation of the alkene moiety. In addition, the encapsulation of [Ru 5 ] clusters inside the nanocapsule is strikingly observed in most of the experimental conditions, as ascertained by HR-MS. Moreover, a thorough DFT study enlightens the nature of the [Ru 5 ] clusters as tb-Ru 5 H 2 (g 6-PhH) 2 (g 6pyz) 3 (2) trapped by two arene moieties of the clip, or as tb-Ru 5 H 2 (g 1pyz) 6 (g 6-pyz) 3 (3) trapped between the two Zn-porphyrin units of the nanocapsule. Both options fulfill the Wade-Mingos counting rules, i.e. 72 CVEs for the closo tb. The trapped [Ru 5 ] metallic clusters are proposed to be the first-grown seeds of subsequent formation of the subnanometric RuNP. Moreover, the double role of the nanocapsule in stabilising B0.7 nm NPs and also in hosting ultra-small Ru clusters, is unprecedented and may pave the way towards the synthesis of ultrasmall metallic clusters for catalytic purposes