{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,12]],"date-time":"2026-05-12T22:25:55Z","timestamp":1778624755246,"version":"3.51.4"},"reference-count":22,"publisher":"MDPI AG","issue":"14","license":[{"start":{"date-parts":[[2019,7,23]],"date-time":"2019-07-23T00:00:00Z","timestamp":1563840000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Comenius University Science Park","award":["ITMS: 26240220086"],"award-info":[{"award-number":["ITMS: 26240220086"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>Four novel isatin hydrazones containing bipyridyl fragments were synthesized as potential ON\/OFF switches. Hydrazone Z-isomers exhibit high thermal stability. The characteristic photochemical reaction for all studied hydrazones is the Z\u2013E isomerization in CHCl3. After irradiation of hydrazones 1 and 2 in dimethylformamide (DMF), the photoreaction products are tautomers. When using light with the appropriate wavelength, the photo-tautomerization reaction is reversible. In these conditions, studied hydrazones have ON\/OFF switch properties. In the case of hydrazones 1 and 2, by alternating heat and light stimulation it is possible to control the isomerization process reversibly. In the presence of fluoride ions, NH hydrogen from the studied hydrazones is cleaved, and the corresponding anions are formed. The resulting anions of Z-isomers are changed to the corresponding E-isomer at room temperature.<\/jats:p>","DOI":"10.3390\/molecules24142668","type":"journal-article","created":{"date-parts":[[2019,7,23]],"date-time":"2019-07-23T10:44:51Z","timestamp":1563878691000},"page":"2668","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["ON\/OFF Photostimulation of Isatin Bipyridyl Hydrazones: Photochemical and Spectral Study"],"prefix":"10.3390","volume":"24","author":[{"given":"R\u00f3bert","family":"\u0160andrik","sequence":"first","affiliation":[{"name":"Faculty of Natural Sciences, Institute of Chemistry, Comenius University, Ilkovi\u010dova 6, Mlynsk\u00e1 dolina CH-2, SK-842 15 Bratislava, Slovakia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5402-8098","authenticated-orcid":false,"given":"Pavol","family":"Tisovsk\u00fd","sequence":"additional","affiliation":[{"name":"Faculty of Natural Sciences, Institute of Chemistry, Comenius University, Ilkovi\u010dova 6, Mlynsk\u00e1 dolina CH-2, SK-842 15 Bratislava, Slovakia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Klaudia","family":"Csicsai","sequence":"additional","affiliation":[{"name":"Faculty of Natural Sciences, Institute of Chemistry, Comenius University, Ilkovi\u010dova 6, Mlynsk\u00e1 dolina CH-2, SK-842 15 Bratislava, Slovakia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jana","family":"Donovalov\u00e1","sequence":"additional","affiliation":[{"name":"Faculty of Natural Sciences, Institute of Chemistry, Comenius University, Ilkovi\u010dova 6, Mlynsk\u00e1 dolina CH-2, SK-842 15 Bratislava, Slovakia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Martin","family":"G\u00e1plovsk\u00fd","sequence":"additional","affiliation":[{"name":"Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Comenius University, Odboj\u00e1rov 10, SK-832 32 Bratislava, Slovakia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"R\u00f3bert","family":"Sokol\u00edk","sequence":"additional","affiliation":[{"name":"Faculty of Natural Sciences, Institute of Chemistry, Comenius University, Ilkovi\u010dova 6, Mlynsk\u00e1 dolina CH-2, SK-842 15 Bratislava, Slovakia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3995-2565","authenticated-orcid":false,"given":"Juraj","family":"Filo","sequence":"additional","affiliation":[{"name":"Faculty of Natural Sciences, Institute of Chemistry, Comenius University, Ilkovi\u010dova 6, Mlynsk\u00e1 dolina CH-2, SK-842 15 Bratislava, Slovakia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Anton","family":"G\u00e1plovsk\u00fd","sequence":"additional","affiliation":[{"name":"Faculty of Natural Sciences, Institute of Chemistry, Comenius University, Ilkovi\u010dova 6, Mlynsk\u00e1 dolina CH-2, SK-842 15 Bratislava, Slovakia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2019,7,23]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1809","DOI":"10.1039\/C1CS15179G","article-title":"Photoisomerization in different classes of azobenzene","volume":"41","author":"Bandara","year":"2012","journal-title":"Chem. 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