Self‐Assembled Tetragonal Prismatic Molecular Cage Highly Selective for Anionic π Guests |
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Authors: | Cristina García‐Simón Marc Garcia‐Borràs Dr Laura Gómez Dr Isaac Garcia‐Bosch Dr Sílvia Osuna Prof Marcel Swart Dr Josep M Luis Prof Concepció Rovira Prof Manuel Almeida Dr Inhar Imaz Prof Daniel Maspoch Dr Miquel Costas Dr Xavi Ribas |
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Institution: | 1. QBIS Group, Departament de Química, Institut de Química Computacional I Catàlisis (IQCC), Universitat de Girona, Campus Montilivi, E17071 Girona, Catalonia (Spain), Fax: (+34)?972‐41‐81‐50;2. Institut de Química Computacional i Catàlisis (IQCC) and Departament de Química, Universitat de Girona, Campus Montilivi, E17071 Girona, Catalonia (Spain);3. Institució Catalana de Recerca i Estudis Avan?ats (ICREA), Pg. Lluís Companys 23, E08010 Barcelona, Catalonia (Spain);4. Institut de Ciència de Materials de Barcelona (ICMAB‐CSIC), Campus UAB, 08193 Bellaterra, Catalonia (Spain);5. Departamento de Química, IST/ITN, Instituto Superior Técnico / CFMCUL, P‐2686‐953 Sacavém (Portugal);6. CIN2(ICN‐CSIC), Catalan Institute of Nanotechnology, Esfera UAB, 08193 Bellaterra, Catalonia (Spain) |
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Abstract: | The metal‐directed supramolecular synthetic approach has paved the way for the development of functional nanosized molecules. In this work, we report the preparation of the new nanocapsule 3? (CF3SO3)8 with a A4B2 tetragonal prismatic geometry, where A corresponds to the dipalladium hexaazamacrocyclic complex Pd‐1 , and B corresponds to the tetraanionic form of palladium 5,10,15,20‐tetrakis(4‐carboxyphenyl)porphyrin ( 2 ). The large void space of the inner cavity and the supramolecular affinity for guest molecules towards porphyrin‐based hosts converts this nanoscale molecular 3D structure into a good candidate for host–guest chemistry. The interaction between this nanocage and different guest molecules has been studied by means of NMR, UV/Vis, ESI‐MS, and DOSY experiments, from which highly selective molecular recognition has been found for anionic, planar‐shaped π guests with association constants (Ka) higher than 109 M ?1, in front of non‐interacting aromatic neutral or cationic substrates. DFT theoretical calculations provided insights to further understand this strong interaction. Nanocage 3? (CF3SO3)8 can not only strongly host one single molecule of M(dithiolene)2 complexes (M=Au, Pt, Pd, and Ni), but also can finely tune their optical and redox properties. The very simple synthesis of both the supramolecular cage and the building blocks represents a step forward for the development of polyfunctional supramolecular nanovessels, which offer multiple applications as sensors or nanoreactors. |
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Keywords: | cage compounds density functional calculations gold anionic guests host– guest systems self‐assembly |
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