Reversible Color and Shape Changes of Nanostructured Fibers of a Macrocyclic π-Extended Thiophene Hexamer Promoted by Adsorption and Desorption of Organic Vapor

Abstract

A phenyl-substituted macrocyclic π-extended thiophene hexamer 1, composed of four thienylene-ethynylene and two thienylene-vinylene units, has a solid-state structure in which π−π, CH−π, and van der Waals interactions occur. Slow addition of acetone to a solution of 1 in CS 2 produces a yellow nanostructured fiber 1-A containing a 1:1.5:1 ratio of 1, acetone, and CS 2 . Over a 2 min period at 25 °C, 1-A gradually changes to an orange fiber 1-B containing a 1:0.5:1 ratio of 1, acetone, and CS 2 . On exposure to acetone vapor, 1-B regenerates 1-A (vapochromism), and removal of all solvents from 1-A and 1-B generates a red-orange fiber 1-C, which upon brief immersion in acetone/CS 2 produces 1-A. Furthermore, 1-C is converted to orange yellow fiber 1-D upon exposure to acetone vapor for 1 s at 25 °C. Analysis of the horizontal and vertical profiles of the X-ray diffraction (XRD) patterns shows that removal of solvent from 1-A reversibly creates 1-B in conjunction with a shape and size change along with arching.

Long Afterglow of a Nonporous Coordination Polymer with Tunable Room-Temperature Phosphorescence by the Doping of Dye Molecules

“…Besides the organic ligand linkers, the incorporation of guests can also adjust the emission properties of MOFs. To date, a large number of MOF-based host–guest systems have been reported. ,− However, there are extremely rare examples of guest molecules doped in nonporous CPs. , In this paper, we report one nonporous CP, {Zn­(IPA)­(MIM) 2 } ( 1 ) (IPA = iso-phthalic acid, MIM = 2-methylimidazole), with a long-lasting lifetime up to 552 ms. The crystal structure, photophysical properties, and periodic density functional theory calculations of 1 have been well studied.…”

Liquid Crystal Nanoparticle Actuator by Polymer Surfactant-Assisted Assembly for Fabricating Bioinspired Smart Interface with Adjustable Light and Changeable Color

“…Functional bionic materials, whose light and color can alter in response to environmental changes, attract increasing amounts of interest. − Smart bionic surfaces with controllable transmittance, self-shading, and color tuning have become a developing area of research. − The controlled light transmission technology has been applied to glass to create smart windows and switchable sunglasses, which not only provides a more comfortable environment but also can save energy, helping to warm in winter and cool in summer. − Liquid crystal (LC) materials can be used as switches controlling light transmission because of the directional arrangement of their molecules in different electrical states. − When they are in random orientations within a droplet, the LC molecules are in an opaque state (“off” state). In an electric field, LC molecules can be directionally aligned, reducing the refraction index and turning the LC clear (“on” state).…”

Switchable Supramolecular Jalousie Constructed from a Fluorenone Macrocycle

“…Organic crystal materials have attracted enormous attention in the past decades due to their extensive applications in optoelectronic devices, − stimuli-responsive materials, − separation, − and pharmaceuticals. − So far, most of the organic crystal materials have been prepared from small molecules, and their functions have been realized by trial and error. In recent years, organic macrocycles containing both functional skeletons and cavities have been proved to be good candidates for constructing crystal materials. − Moreover, the extensive applications of macrocycles in materials science make it essential to have an insight into the precise modulation of their solid-state properties. In general, the rotation of structural units at macrocycles is readily available in solutions and has been well studied. − In the solid state, especially crystals, however, such a rotation is difficult because of the restriction of the lattice and ever-present noncovalent interactions (hydrogen bond, van der Waals force, π···π interactions, etc.).…”