Enhanced lithium electrochromism of atmospheric pressure plasma jet-synthesized tungsten/molybdenum oxide films for flexible electrochromic devices

Enhanced lithium electrochromic performances of mixed organo-tungsten oxide (W _x O _y C _z )/organo-molybdenum oxide (Mo _x O _y C _z ) films by a rapid codeposition onto 40 Ω/□ flexible polyethylene terephthalate/indium tin oxide substrates at a short exposed duration of 23 s using an atmospheric pressure plasma jet (APPJ) at various mixed concentrations of hexacarbonyl precursors [W(CO)₆ and Mo(CO)₆] are investigated. The flexible organo-tungsten–molybdenum oxide (WMo _x O _y C _z ) films demonstrated noteworthy electrochromic performance for 200 cycles of reversible Li⁺ ion intercalation and deintercalation in a 1 M LiClO₄–propylene carbonate electrolyte by the switching measurements of potential sweep from ?1 to 1 V at a scan rate of 50 mV/s and the potential step at ?1 and 1 V, even after being bent 360^o around a 2.5-cm diameter rod for 1,000 cycles. The optical modulation (ΔT) of 61.3 % for MoO _y C _z films at a wavelength of 795.6 nm was significantly improved up to 72.5 % for WMo _x O _y C _z films cosynthesized with an APPJ.     

Optically controllable bistable reflective liquid crystal display

This Letter demonstrates a photo-addressable, bistable reflective liquid crystal display that is based on a dye-doped liquid crystal (DDLC). Bistable bright and dark states can be attained using the 45 deg twisted nematic (TN) and photo-induced isotropic states (PHI) of the DDLC, respectively. Both the 45 deg TN and PHI states can exist stably for tens of hours, and each can be rapidly switched to the other by the isomerization effect using UV and green light. A bistable reflective liquid crystal display is simply fabricated, easily operated, and rapidly switched. It therefore has the potential to be used in portable information systems.     

Nonlinear optical grating diffraction in dye-doped blue-phase liquid crystals

Low-power cw lasers are employed to study grating formation in blue-phase liquid crystals. We observed that undoped samples exhibit vanishingly small optical nonlinearities whereas methyl-red-dye doped samples produce strong nonlinear self-diffraction effects. The nonlinearities are attributed to director axis reorientation, disorder, and lattice distortion by the laser-excited dye molecules. The magnitude of the observed intensity-dependent index coefficient is in the range of 10^-4-10^-3 cm²/Watt.     

New Triterpenoid and Anti-Inflammatory Constituents of Eriobotrya deflexa f. deflexa

Chemistry of Natural Compounds - A new triterpenoid, methyl 2α-(4-hydroxybenzoyl)oxy-3β-hydroxy-urs-12-en-28-oate (1), has been isolated from the leaves of Eriobotrya deflexa f. deflexa,...     

Photophysical and electrochemical properties of 1,7-diaryl-substituted perylene diimides

Substituent effects on the photophysical and electrochemical properties of 1,7-diaryl-substituted perylene diimides (1,7-Ar(2)PDIs) have been carefully explored. Progressive red-shifts of the absorption and emission maxima were observed when the electron-donating ability of these substituents was increased. Linear Hammett correlations of 1/lambda(max) versus sigma(+) were observed in both spectral analyses. The positive slopes of the Hammett plots suggested that the electronic transitions carry certain amounts of photoinduced intramolecular charge-transfer (PICT) character from the aryl substituents to the perylene diimide core which leads to the reduction of the electron density on the substituents. The substituent electronic effects originated mainly from the perturbation of the core PDI HOMO energy level by the substituents. This conclusion was supported by PM3 analyses and confirmed by cyclic voltammetry experiments. More interestingly, the Ph(2)NC(6)H(4)-substituted PDI, 4i, showed an unusual dual-band absorption that spans from 450 to 750 nm. We tentatively assigned these two bands as the charge-transfer band and the PDI core absorption, respectively.     

New Coumarin and Bioactive Constituents of Chionanthus retusus

Chemistry of Natural Compounds - A new coumarin derivative, 7-O-methylparamicoumarin A (1), has been isolated from the roots of Chionanthus retusus, together with seven known compounds. The...     

Nonlinear Optics of Nematic and Blue Phase Liquid Crystals

We present a critical reexamination of individual electronic and collective optical nonlinearities of nematic liquid crystals (NLC) in the context of all-optical transmission switching of femtoseconds – CW lasers, and report recent observations of similar optical nonlinearities in Blue-phase liquid crystals (BPLC) and their utilization in feasibility demonstrations of polarization-free nonlinear grating diffraction and transmission switching of CW as well as pulsed lasers.     

A New Acenaphthylene and Bioactive Constituents of Salvia arisanensis

Chemistry of Natural Compounds - A new acenaphthylene derivative, salviarisanal (1), has been isolated from the aerial part of Salvia arisanensis, together with six known compounds, carnosol (2),...