title: H-Aggregates Granting Crystallization-Induced Emissive Behavior and Ultralong Phosphorescence from a Pure Organic Molecule.
abstract: Solid-state luminescent materials with long lifetimes are the subject of ever-growing interest from both a scientific and a technological point of view. However, when dealing with organic compounds, the achievement of highly efficient materials is limited by aggregation-caused quenching (ACQ) phenomena on one side and by ultrafast deactivation of the excited states on the other. Here, we report on a simple organic molecule, namely, cyclic triimidazole (C9H6N6), 1, showing crystallization-induced emissive (CIE) behavior and, in particular, ultralong phosphorescence due to strong coupling in H-aggregated molecules. Our experimental data reveal that luminescence lifetimes up to 1 s, which are several orders of magnitude longer than those of conventional organic fluorophores, can be realized under ambient conditions, thus expanding the class of organic materials for phosphorescence applications.
authors.affiliation: ISTM-CNR, Istituto di Scienze e Tecnologie Molecolari - Consiglio Nazionale delle Ricerche and INSTM UdR , via Golgi 19, 20133 Milano, Italy.
authors.forename: Elena
authors.identifier: http://orcid.org/0000-0002-2418-7565
authors.initials: E
authors.lastname: Lucenti
authors.affiliation: ISTM-CNR, Istituto di Scienze e Tecnologie Molecolari - Consiglio Nazionale delle Ricerche and INSTM UdR , via Golgi 19, 20133 Milano, Italy.
authors.forename: Alessandra
authors.identifier: http://orcid.org/0000-0002-5020-5544
authors.initials: A
authors.lastname: Forni
authors.affiliation: ISMAC-CNR, Istituto per lo Studio delle Macromolecole - Consiglio Nazionale delle Ricerche and INSTM UdR , Via Corti 12, 20133 Milano, Italy.
authors.forename: Chiara
authors.identifier: http://orcid.org/0000-0001-8722-0417
authors.initials: C
authors.lastname: Botta
authors.affiliation: Department of Chemistry, Università degli Studi di Milano and INSTM UdR , via Golgi 19, 20133 Milano, Italy.
authors.forename: Lucia
authors.identifier: http://orcid.org/0000-0001-5856-5280
authors.initials: L
authors.lastname: Carlucci
authors.affiliation: Department of Chemistry, Università degli Studi di Milano and INSTM UdR , via Golgi 19, 20133 Milano, Italy.
authors.forename: Clelia
authors.identifier: http://orcid.org/0000-0003-3376-8350
authors.initials: C
authors.lastname: Giannini
authors.affiliation: Department of Chemistry, Università degli Studi di Milano and INSTM UdR , via Golgi 19, 20133 Milano, Italy.
authors.forename: Daniele
authors.identifier: http://orcid.org/0000-0002-4490-8825
authors.initials: D
authors.lastname: Marinotto
authors.affiliation: Department of Chemistry, Università degli Studi di Milano and INSTM UdR , via Golgi 19, 20133 Milano, Italy.
authors.forename: Andrea
authors.identifier: http://orcid.org/0000-0001-9537-8652
authors.initials: A
authors.lastname: Previtali
authors.affiliation: Department of Chemistry, Università degli Studi di Milano and INSTM UdR , via Golgi 19, 20133 Milano, Italy.
authors.forename: Stefania
authors.identifier: http://orcid.org/0000-0002-2537-3220
authors.initials: S
authors.lastname: Righetto
authors.affiliation: Department of Chemistry, Università degli Studi di Milano and INSTM UdR , via Golgi 19, 20133 Milano, Italy.
authors.forename: Elena
authors.identifier: http://orcid.org/0000-0003-1781-0360
authors.initials: E
authors.lastname: Cariati