Constitutional isomers of a C₃-symmetric molecule showing different piezochromic behaviours: on–off switching and colour tuning

Abstract

Two constitutional isomers of a C3-symmetric molecule having cyano-vinylene bridges and a phenyl ring core show different piezochromic behaviours, on–off switching and colour tuning upon grinding.

Self‐Assembled α‐Cyanostilbenes for Advanced Functional Materials

“…CS with fluoro substitution and phenothiazine luminescent units show MCF properties with red‐shifted emission, whereas other halogen groups (Cl, Br) did not give rise to this property. Two isomeric C 3 ‐symmetric molecules with a bromo terminal group (Figure D) were found to exhibit MCF, whereas unsubstituted compounds did not show this behavior . Upon grinding, the isomer with inner CN groups, α‐BPAN‐Br (Figure D) exhibited substantial quenching of bluish green emission, which represents a case of fluorescence turn‐off, while the one with CN groups in the outer position, β‐BPAN‐Br , showed a color change from bluish green to deep blue.…”

“…[23c] Copyright 2014, The Royal Society of Chemistry. (D) Adapted with permission . Copyright 2014, The Royal Society of Chemistry.…”

Mechanoresponsive Luminescent Molecular Assemblies: An Emerging Class of Materials

“…Copyright 2014, The Royal Society of Chemistry. Part (d) is adapted with permission . Copyright 2014, The Royal Society of Chemistry.…”

“…After the report on 32 , another research group achieved photoluminescence on–off switching using cyano‐substituted stilbene derivatives. Chang et al have developed C 3 ‐symmetric molecules having p ‐bromophenyl moieties . The authors found that compound 33 having cyano substituents at the α ‐position to the central phenyl moiety exhibits on–off switching in photoluminescence upon mechanical stimuli (Figure d).…”

Structure–Thermodynamic‐Property Relationships in Cyanovinyl‐Based Microporous Polymer Networks for the Future Design of Advanced Carbon Capture Materials

“…[23] The capture of carbon in P1 comes mostly from its high porosity, which clearly relates the uptake in the other networks to their cyanovinyl content, making the latter a very interesting building block for carbon capture. Even for P4, which consists only of cyanostilbene units that are not entirely linear but rather more flexible and could relax into a nonporous condensed state, [24] the functional group maintains the polymer with an uptake of 32 mg of CO2 per 1 g of material. It is noted however that selectivities of these networks over N2 were relatively poor.…”