Control of Self-Assembly of a 3-Hexen-1,5-diyne Derivative: Toward Soft Materials with an Aggregation-Induced Enhancement in Emission

Abstract

The supramolecular architectures of a fluorophore are controlled through the design of a conjugated polycatenar molecule, the self-assembly of which can be addressed toward a columnar liquid-crystalline phase and organogels. Thus, depending on the environmental conditions for self-assembly, compound CA9 organizes into an unprecedented hexagonal columnar mesophase in the condensed state, in which half a molecule constitutes the slice of the column, or into a rectangular mesomorphic-like organization in the presence of apolar solvents such as cyclohexane and dodecane, at a concentration in which fibers form and gelling conditions are fulfilled. In this Col(r)-type arrangement, the organization within the columns depends on the solvent. All of the materials prepared show luminescence, and moreover, a remarkable 3-fold increase in fluorescence intensity was observed in going from the solution to the gel state.

Mesomorphic Organization and Thermochromic Luminescence of Dicyanodistyrylbenzene‐Based Phasmidic Molecular Disks: Uniaxially Aligned Hexagonal Columnar Liquid Crystals at Room Temperature with Enhanced Fluorescence Emission and Semiconductivity

“…Among others, the intermolecular head‐to‐tail coupling of local dipoles is operating for the formation of molecular disk, due to the spatial restriction induced by phasmidic polycatenar structure (see Figure 7 for the coupling scheme). We could verify that the number of molecules per slice is about two, through the density calculation method based on the XRD data 14. The density of GDCS in the LC state at 30 °C was calculated to be 0.46 Z , where Z is the number of molecules per unit cell.…”

Self-Assembly of Silver(I) and Gold(I) N-Heterocyclic Carbene Complexes in Solid State, Mesophase, and Solution

“…47−50 Various techniques such as nuclear magnetic resonance (NMR), powder X-ray diffraction (PXRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), small-angle X-ray scattering (SAXS), and small-angle neutron scattering (SANS) have been employed to study the formation of gels. 51 −53 Gels have been used to produce materials for optical, 54,55 electrical, 56 catalytic, 57 sensing, 58,59 chemical processing, foods, and drug delivery applications. 60−62 Recently, reviews on the incorporation of metal ions in gels appeared.…”

Nanophotonics and supramolecular chemistry

“…The formation of head-head assembly is highly advantageous for nonlinear optical activity. Sierra, Barluenga, and coworkers reported the aggregation-induced enhanced emission effect in self-assembled structures of 1,6-bis(4-hydroxyphenyl)-3-hexen-1,5-diyne bearing two bulky end groups derived from 3,4,5-tris(3,4,5-trihydroxybenzyloxy)benzoic acid (Figure 2A), probably due to the restriction of intramolecular rotation [30]. This property makes it possible to obtain molecular self-assemblies as liquid-crystalline phases or organogels with intense luminescence.…”