Electron transfer photochromism of solid-state supramolecules constructed by cucurbit[n]uril (n = 5-8) and 1-(4-carboxybenzyl)-4-[2-(4-pyridyl)-vinyl]-pyridinium chloride

Incorporation of the potential photochromic compound 1-(4-carboxybenzyl)-4-[2-(4-pyridyl)-vinyl]-pyridinium chloride (guest 1+·Cl-) into the macrocyclic hosts cucurbit[n]uril (n = 5-8, Q[n]) generated a new kind of photochromic material. 1H NMR experiments confirm...

Photomechanical Azobenzene Crystals

Photomechanically responsive materials are promising candidates for future smart actuator applications. The photo-responsive behaviors originate from the photoisomerization of photochromic molecules. A typical photochromic compound, azobenzene, has been studied extensively in the solution state and has played a crucial role in the photomechanical behaviors of materials such as polymers and gels, via chemical bridging with their matrix. In contrast to polymers and gels, the photomechanical attributes of molecular crystals have not progressed to the same degree, due to their rigidity and fragility. However, the past decade has witnessed an increasing number of reports of the photomechanical motion of molecular crystals, including azobenzene crystals. This paper reviews the current state-of-the-art of mechanically responsive azobenzene crystals, including the history, crystal design strategy, and future promising applications.

Studies on dynamics and isomerism in supercooled photochromic compound Aberchrome 670 with the use of different experimental techniques

Broadband Dielectric Spectroscopy (BDS) was applied to monitor Z–E isomerization in a fulgide-type photochromic compound, Aberchrome 670 (Ab670).

Photochromic benzo[b]phosphole oxide with excellent thermal irreversibility and fatigue resistance in the thin film solid state via direct attachment of dithienyl units to the weakly aromatic heterocycle

Direct attachment of a photoactive bis-thienyl unit to benzo[b]phosphole oxide has led to a new photochromic compound that shows excellent performance in ambient thin film conditions.

Stealth fast photoswitching of negative photochromic naphthalene-bridged phenoxyl-imidazolyl radical complexes

A novel negative photochromic compound, Np-PIC, shows the fast thermal back reaction in the millisecond time scale.

Crystal structure of the photochromic compound 1-(2-cyano-1,5-dimethyl- 4-pyrryl)-2-(2-methyl-5-formyl-3-thienyl)-3,3,4,4,5,5-hexafluorocyclopent- 1-ene, C18H12F6N2OS

C18H12F6N2OS, monoclinic, P21/c (no. 14), a = 16.435(1) Å, b = 12.9012(9) Å, c = 8.6788(5) Å, β = 90.007(4)°, V = 1840.2 Å3, Z = 4, Rgt(F) = 0.0531, wRref(F2) = 0.1399, T = 293 K.

Colorimetric Detection of Nitroaromatics Using Organic Photochromic Compounds

An organic photochromic compound is explored as a new portable colorimetric sensor for nitroaromatics. This photochromic compound switches from colourless to pink upon exposure to ultraviolet light. In the presence of nitroaromatic explosive derivatives the photoswitching behaviour of the dithienylethene is suppressed, while a potential false positive (toluene) has little effect. The degree of photoswitching inhibition was determined by comparing the integrated visible absorption with the concentration of the analyte to give the pseudo Stern–Volmer constant (KPSV). The KPSVs measured varied from 12900 (p-nitrotoluene) to 236 M–1 (toluene), which were directly related to the analyte absorption at the excitation wavelength.