{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,22]],"date-time":"2026-01-22T17:12:20Z","timestamp":1769101940939,"version":"3.49.0"},"reference-count":56,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2020,5,25]],"date-time":"2020-05-25T00:00:00Z","timestamp":1590364800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["UID\/QUI\/00616\/2019"],"award-info":[{"award-number":["UID\/QUI\/00616\/2019"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Instituto Polit\u00e9cnico de Lisboa","award":["Project IPL\/2016\/NoSeMeTox\/ISEL"],"award-info":[{"award-number":["Project IPL\/2016\/NoSeMeTox\/ISEL"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>A new topological design of fluorescent probes for sensing copper ion is disclosed. The calix[4]arene-oxacyclophane (Calix-OCP) receptor, either wired-in-series in arylene-alt-ethynylene conjugated polymers or standing alone as a sole molecular probe, display a remarkable affinity and selectivity for Cu(II). The unique recognition properties of Calix-OCP system toward copper cation stem from its pre-organised cyclic array of O-ligands at the calixarene narrow rim, which is kept in a conformational rigid arrangement by a tethered oxacyclophane sub-unit. The magnitude of the binding constants (Ka = 5.30 \u2212 8.52 \u00d7 104 M\u22121) and the free energy changes for the inclusion complexation (\u2212\u0394G = 27.0 \u2212 28.1 kJmol\u22121), retrieved from fluorimetric titration experiments, revealed a high sensitivity of Calix-OCP architectures for Cu(II) species. Formation of supramolecular inclusion complexes was evidenced from UV-Vis spectroscopy. The new Calix-OCP-conjugated polymers (polymers 4 and 5), synthesized in good yields by Sonogashira\u2013Hagihara methodologies, exhibit high fluorescence quantum yields (\u03a6F = 0.59 \u2212 0.65). Density functional theory (DFT) calculations were used to support the experimental findings. The fluorescence on\u2013off behaviour of the sensing systems is tentatively explained by a photoinduced electron transfer mechanism.<\/jats:p>","DOI":"10.3390\/molecules25102456","type":"journal-article","created":{"date-parts":[[2020,5,25]],"date-time":"2020-05-25T11:42:02Z","timestamp":1590406922000},"page":"2456","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":15,"title":["Highly Sensitive and Selective Fluorescent Probes for Cu(II) Detection Based on Calix[4]arene-Oxacyclophane Architectures"],"prefix":"10.3390","volume":"25","author":[{"given":"Alexandra I.","family":"Costa","sequence":"first","affiliation":[{"name":"Departamento de Engenharia Qu\u00edmica, Instituto Superior de Engenharia de Lisboa, Instituto Polit\u00e9cnico de Lisboa, R. Conselheiro Em\u00eddio Navarro, 1, 1959-007 Lisboa, Portugal"},{"name":"Centro de Qu\u00edmica-Vila Real, Universidade de Tr\u00e1s-os-Montes e Alto Douro, 5001-801 Vila Real, Portugal"}]},{"given":"Patr\u00edcia D.","family":"Barata","sequence":"additional","affiliation":[{"name":"Departamento de Engenharia Qu\u00edmica, Instituto Superior de Engenharia de Lisboa, Instituto Polit\u00e9cnico de Lisboa, R. Conselheiro Em\u00eddio Navarro, 1, 1959-007 Lisboa, Portugal"},{"name":"Centro de Qu\u00edmica-Vila Real, Universidade de Tr\u00e1s-os-Montes e Alto Douro, 5001-801 Vila Real, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3529-2069","authenticated-orcid":false,"given":"Carina B.","family":"Fialho","sequence":"additional","affiliation":[{"name":"Departamento de Engenharia Qu\u00edmica, Instituto Superior de Engenharia de Lisboa, Instituto Polit\u00e9cnico de Lisboa, R. Conselheiro Em\u00eddio Navarro, 1, 1959-007 Lisboa, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9068-2847","authenticated-orcid":false,"given":"Jos\u00e9 V.","family":"Prata","sequence":"additional","affiliation":[{"name":"Departamento de Engenharia Qu\u00edmica, Instituto Superior de Engenharia de Lisboa, Instituto Polit\u00e9cnico de Lisboa, R. Conselheiro Em\u00eddio Navarro, 1, 1959-007 Lisboa, Portugal"},{"name":"Centro de Qu\u00edmica-Vila Real, Universidade de Tr\u00e1s-os-Montes e Alto Douro, 5001-801 Vila Real, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2020,5,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"187","DOI":"10.1039\/CS9922100187","article-title":"Molecular Fluorescent Signalling with \u2019Fluor-Spacer-Receptor\u2018 Systems: Approaches to Sensing and Switching Devices via Supramolecular Photophysics","volume":"21","author":"Bissell","year":"1992","journal-title":"Chem. Soc. 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