Polymorphism-dependent aggregation induced emission of a push–pull dye and its multi-stimuli responsive behavior

Abstract

A push–pull dye with AIE polymorphism-dependent properties shows mechano-, thermo- and chrono-chromism associated with stimuli-induced surface structural defects.

Structure–activity relationship for the solid state emission of a new family of “push–pull” π-extended chromophores

“…Crystal structures of the series 1, 10a and compounds 2b 12 and 5a 13 were previously reported by us, together with a thorough discussion, supported with DFT and TDDFT calculations, [11][12][13] of the structure-optical property relationships governing their emissive behaviour. It was found that their AIE properties were strictly related to their crystal structure, which is able to activate a RIR process.…”

“…All the compounds reported in Table 1 show a very low PL QY in solution, which does not depend much on the polarity of the solvent. Compounds 1a, 10a 2b, 12 2e, 3a, 3b and 5a 13 show solvatochromic behaviour related to their push-pull molecular structure (see ESI †) without any relevant variation in emission intensity.…”

“…1) crystallizes in four different polymorphs all showing different emission colors, and that the emission color can be tuned via heating and grinding in the solid state, highlighting the potential application for stimuli responsive solid-state materials. 13 In this paper, we report our further achievements into the ne tuning of the previously proposed molecular "push-pull" structures in order to investigate their potential in terms of AIE, to match requirements for optoelectronic and sensing applications. We will discuss the optical properties and the AIE and solid state behavior of a series of compounds in which the original molecular structure has been systematically varied ( Fig.…”

Tricolor Luminescence Switching by Thermal and Mechanical Stimuli in the Crystal Polymorphs of Pyridyl‐substituted Fluorene

“…We considered that, connecting the groups of hydrogen bonding factor,e .g.,o xygen-containing or nitrogen-containing groups,t ot he two sides of fluorene may achievet he same effect as fluorenone for the construction of stimuli-responsive SLS molecules.T his approach for the design of functional molecules may likewise result in metastables olid/ crystalline structures because of the competition between p-p stacking and hydrogen bonding, which is ap rerequisite of the reversible phase transformationso fs timuli-responsive SLS molecules. [42][43][44][45][46][47][48][49][50] In this paper,w er eported as mall organic molecule, 4,4'-(9,9-dimethyl-9H-fluorene-2,7-diyl)dipyridine (MFDP, Scheme 1), which exhibited three different crystal polymorphs with different luminescentc olor.M oreover,a ll three polymorphsd isplayh igh solid luminescente fficiency and showed an ovel tricolor fluorescent switching from violet to blue and to green upon heating or grinding. The single crystalso ft he three crystal polymorphs were obtained, and their phase transformation and photophysical properties were comprehensively investigated.…”

One-Pot Click Access to a Cyclodextrin Dimer-Based Novel Aggregation Induced Emission Sensor and Monomer-Based Chiral Stationary Phase

“…In contrast to aggregation-caused quenching (ACQ) of traditional fluorophore, TPE derivatives can exhibit strong emission when they are aggregated or in the solid state [29,30,31]. At the same time, tetra-phenyl ethylene (TPE) is a typical fluorophore which processes the advantages of facile synthesis and easy structural modification; numerous functional groups can be attached to it through simple reactions, so it was chosen as the AIE fluorescence core in this study.…”