Stimuli-Responsive Benzothiadiazole Derivative as a Dopant for Rewritable Polymer Blends

A new rod-shaped benzothiadiazole fluorophore, namely, 4,7-di-(4-nonylphenyl)benzo[c][1,2,5]thiadiazole, which strongly emits fluorescence both in solution and in solid state has been synthesized, and its photophysical properties were rationalized with the help of density functional theory calculati...

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Detalles Bibliográficos
Autores: Echeverri, Marcelo, Ruiz, Constanza, Gámez-Valenzuela, S., Alonso Navarro, Matías, Gutiérrez-Puebla, Enrique, José L. Serrano, Ruiz Delgado, M. Carmen, Gómez-Lor, Berta
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2020
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/413926
Acceso en línea:http://hdl.handle.net/10261/413926
https://www.scopus.com/inward/record.uri?eid=2-s2.0-85080137159&doi=10.1021%2Facsami.9b21209&partnerID=40&md5=ebc550da7e36d9d00414f7e20a77ff24
Access Level:acceso abierto
Palabra clave:benzothiadiazole
fluorescence
mechanochromism
phase transformation
polymorphism
thermochromism
Descripción
Sumario:A new rod-shaped benzothiadiazole fluorophore, namely, 4,7-di-(4-nonylphenyl)benzo[c][1,2,5]thiadiazole, which strongly emits fluorescence both in solution and in solid state has been synthesized, and its photophysical properties were rationalized with the help of density functional theory calculations. This molecule crystallizes in two distinct light-emitting crystalline phases, which can be interconverted in response to pressure, temperature, and solvent vapors. Powder X-ray diffraction indicates that in both polymorph, molecules adopt a lamellar packing, the different interlayer spacing being the main difference between the two structures. Single-crystal analysis of one of the polymorphs allows us to identify weak interaction planes, which presumably facilitates the polymorphic transformation through mechanically or thermally induced sliding processes. The polymorphic transformation and the origin of the switchable fluorescence have been rationalized through a spectroscopic and theoretical study. This study suggests that the different colors observed are due to different intermolecular aromatic interactions owing to the displacement of the molecules with respect to the layer normal. Interestingly, blending this molecule with a biodegradable polymer such as poly(vinyl alcohol) gives rise to a thermally activated reversible switchable fluorescent system, which entitles this material as an attractive candidate for technological applications, such as thermal sensors, security inks, or rewritable paper. © © 2020 American Chemical Society.