Supramolecular engineering bridges molecular assembly with macromolecular charge-transfer salts, promising the design to construct supramolecular architectures that integrate cooperative properties ...difficult or impossible to find in conventional lattices. Here, we report the crystal engineering design and kinetic growth of one-dimensional supramolecular wires composed of bis(ethylenedithio)tetrathiafulvalene (ET+) cation and polymeric CuN(CN)22 – anion. A bulk ferromagnetic order is discovered for filling up the gap where strong ferromagnetism is missing in such ET molecule-based charge-transfer salts. Metallicity is induced by electric current from the semiconducting wire, which is attributed to strain effect by tuning its close molecular contact. This structural feature is evidenced through the combination of various mechanistic spectroscopic studies. Electric dipole is established from the close molecular contacts and is suggestive to stabilize ferromagnetic spin interaction through anions bridging spin sites. The breakthrough shown here provides a pathway to explore low-dimensional supramolecular materials exhibiting strong electron correlation, metallicity, and ferromagnetism.
We report the first instance of observing the phototriggered isomerization of dmso ligands on a bis sulfoxide complex, Ru(bpy)
2
(dmso)
2
, in the crystalline solid state. The solid-state UV-vis ...spectrum of the crystal demonstrates an increase in optical density around 550 nm after irradiation, which is consistent with the solution isomerization results. Digital images of the crystal before and after irradiation display a notable color change (pale orange to red) and cleavage occurs along planes, (1&cmb.macr;01) and (100), during irradiation. Single crystal X-ray diffraction data also confirms that isomerization is occurring throughout the lattice and a structure that contains a mix of the
S
,
S
and
O
,
O
/
S
,
O
isomer was attained from a crystal irradiated
ex situ
.
In situ
irradiation XRD studies reveal that the percentage of the O-bonded isomer increases as a function of 405 nm exposure time.
We report the first observation of the phototriggered isomerization of dmso ligands on a bis sulfoxide complex, Ru(bpy)
2
(dmso)
2
, in the crystalline solid state.
A series of molecular engineered organic glasses have been prepared to exploit the use of complementary Ar−ArF interactions to improve poling efficiency. These self-organized molecular glasses have ...also been used as host in the binary chromophore system to further improve the number density of chromophores and r 33 values. Ultrahigh r 33 values (up to 327 pm/V at the wavelength of 1310 nm) and good temporal stability could be achieved in these materials.
Four crystalline polymorphs of the proinsecticide chlorfenapyr 4-bromo-2-(4-chlorophenyl)-1-ethoxymethyl-5-trifluoromethyl-1H-pyrrole-3-carbonitrile have been identified and characterized by ...polarized light optical microscopy, differential scanning calorimetry, Raman spectroscopy, X-ray diffraction, and electron diffraction. Three of the four structures were considered polytypic. Chlorfenapyr polymorphs show similar lethality against fruit flies (Drosophila melanogaster) and mosquitoes (Anopheles quadrimaculatus) with the least stable polymorph showing slightly higher lethality. Similar activities may be expected to be consistent with structural similarities. Knockdown kinetics, however, depend on an internal metabolic activating step, which further complicates polymorph-dependent bioavailability.
Diarylethene‐based photoswitches have become very popular over the last few decades for potential applications in chemistry, materials science, and biotechnology due to their unique physical and ...chemical properties. We report the isomeric separation of a diarylethene‐based photoswitchable compound using high‐performance liquid chromatography. The separated isomers were characterized by ultraviolet‐visible spectroscopy and mass spectrometry confirmed the isomeric nature of the compounds. The isomers were purified by preparative high‐performance liquid chromatography, providing fractionated samples to study the isomers individually. A total amount of 13 mg of an isomer of interest was fractionated from a solution of 0.4 mg/ml of the isomeric mixture. Because the preparative high‐performance liquid chromatographic method required large quantities of solvent, we explored the use of supercritical fluid chromatography as an alternative separation mode which, to the best of our knowledge, is the first time this technique is used to separate diarylethene‐based photoswitchable compounds. Supercritical fluid chromatography provided faster analysis times while maintaining sufficient baseline resolution for the separated compounds and consuming less organic solvent in the mobile phase compared to high‐performance liquid chromatography. It is proposed that the supercritical fluid chromatographic method be upscaled and used in future fractionation of the diarylethene isomeric compounds, becoming a more environmentally benign approach for compound purification.
Dithienylethenes (DTEs) are a promising class of organic photoswitches that can be used to create crystalline solids with properties controlled by light. However, the ability of DTEs to adopt ...multiple conformations, only one of which is photoactive, complicates the rational design of these materials. Herein, the synthesis and structural characterization of 19 crystalline solids containing a single DTE molecule are described. A novel
D
–
D
analysis of the molecular geometries obtained from rotational potential energy surface calculations and the ensemble of experimental structures were used to construct a crystal landscape for DTE. Of the 19 crystal structures, 17 contained photoinactive DTE rotamers and only 2 were photoactive. These results highlight the challenges associated with the design of these materials. Overall, the
D
–
D
analysis described herein provides rapid, effective and intuitive means of linking the molecular structure to photoactivity that could be applied more broadly to afford a general strategy for producing photoactive diarylethene-based crystalline solids.
The synthesis and structure of a novel ortho-fluoroazobenzene, methyl 4-bromo-3-((2,6-difluorophenyl)diazenyl) benzoate is described. The title molecule crystallizes in the centrocemetric space group
...P
-1 with two rotomer molecules of the title compound in the asymmetric unit. The position of ortho-fluoro azo rings differ between the two rotomers with one molecule having a rotation angle of 4.4° and the other molecule having a rotation angle of 76.9° with respect to the methyl 4-bromobenzoate. Due to the tight packing the pure molecule was not seen to be photoactive. However, in solution the absorption bands in the visible region show a separation of about 20 nm as expected for
o
-fluoroazobenzene. A comparison to related and previously published co-crystals of substituted azobenzenes are presented.
Graphic Abstract
The structure of a novel ortho-fluoroazobenzene, methyl 4-bromo-3-((2,6-difluorophenyl)diazenyl) benzoate reveals the presence of two crystallographically unique rotomers in the lattice, and although the molecule is photoactive in solution, the close-packed lattice appears to inhibit photo-induced structural reorganization in the crystalline state.
