Polymorphism‐Dependent Emission for Di(p‐methoxylphenyl)dibenzofulvene and Analogues: Optical Waveguide/Amplified Spontaneous Emission Behaviors

Abstract

The synthesis and optical investigations of di(p‐methoxylphenyl)dibenzofulvene (1) and its analogues 2, 3, 4, 5, 6, and 7 with different lengths of alkoxyl chains are presented. All of these molecules exhibit emission in the solid state. The following interesting properties are reported for compound 1: 1) the solid‐state fluorescence of 1 is dependent on the polymorphism forms; the two crystalline forms 1a and 1b are strongly blue‐ and yellow‐green‐emissive, whereas the amorphous solid is weakly fluorescent with orange emission; 2) on the basis of crystal‐structural analysis, the intermolecular interactions will restrict the internal rotations, leading to fluorescence enhancement for the two crystalline forms 1a and 1b; however, the difference in emission color between 1a and 1b is ascribed to the molecular conformational alteration; 3) the solid‐state fluorescence of 1 can be tuned by heating and cooling as well as grinding. Importantly, microrods of 1a and 1b exhibit outstanding optical waveguide behaviors. Moreover, amplified spontaneous emission for 1b and multimode‐lasing behavior for 1a are presented. Besides the studies of compound 1, the crystal structures and solid‐state fluorescence behaviors of 2, 3, 4, 5, 6, and 7 are also described.

Manipulation of the Aggregation and Deaggregation of Tetraphenylethylene and Silole Fluorophores by Amphiphiles: Emission Modulation and Sensing Applications

“…Some of us reported the polymorphism-dependent emission for di(p-methoxylphenyl)-dibenzofulvene (1, Scheme 1). 45 Three solid-state emission forms with different emission colors were found for 1; two crystalline forms are strongly emissive, whereas the amorphous solid is weakly fluorescent. Interestingly, the formation of three emission forms can be controlled with the aid of CTAB (cetyltrimethylammonium bromide).…”

Building Functional Materials via Self-assembly of Calixazacrowns

“…On the contrary, the shift in the color of the polymorphs of 1 may be ascribed to different π-π stacking between adjacent calixarene dimer units, as 1 adopts the same conformation. [31][32][33][34][35] Combining AIE with control of packing arrangement to produce materials that exhibit stimuli-responsive switching between two or more solid phases with different emission characteristics still remains a challenge, [35][36][37][38][39] and would provide potential applications for smart materials. [40,41] The blue emitting crystals of 1 suffered thermal treatment for the sake of stimuli-responsive behavior.…”

Tuning the Solid State Emission of the Carbazole and Cyano‐Substituted Tetraphenylethylene by Co‐Crystallization with Solvents

“…For instance, some of us reported two crystalline forms of di( p ‐methoxylphenyl) dibenzofulvene exhibiting blue and green emissions with high quantum yields, while the amorphous solid emits weakly with orange emission. [17a] Different emissive behaviors of the two crystalline forms was attributed to the fact that molecules of di( p ‐methoxylphenyl) dibenzofulvene within the two crystalline forms adopt different conformations. Furthermore, the controllable formation of three emissive forms of di( p ‐methoxylphenyl) dibenzofulvene was realized in the presence of cetyl trimethylammonium bromide (CTAB).…”