Correlating structure and photophysical properties in thiazolo[5,4-]thiazole crystal derivatives for use in solid-state photonic and fluorescence-based optical devices.

There is a growing demand for new fluorescent small molecule dyes for solid state applications in the photonics and optoelectronics industry. Thiazolo[5,4-]thiazole (TTz) is an organic heterocycle moiety which has previously shown remarkable properties as a conjugated polymer and in solution-based studies. For TTz-based small molecules to be incorporated in solid-state fluorescence-based optical devices, a thorough elucidation of their structure-photophysical properties needs to be established.

Degradation Kinetics of Organic-Inorganic Hybrid Materials from Micro-Raman Spectroscopy and Density-Functional Theory: The Case of β-ZnTe(en).

Organic-inorganic hybrid materials often face a stability challenge. β-ZnTe(en) , which uniquely has over 15-year real-time degradation data, is taken as a prototype structure to demonstrate an accelerated thermal aging method for assessing the intrinsic and ambient-condition long-term stability of hybrid materials. Micro-Raman spectroscopy is used to investigate the thermal degradation of β-ZnTe(en) in a protected condition and in air by monitoring the temperature dependences of the intrinsic and degradation-product Raman modes.

Leveraging Coupled Solvatofluorochromism and Fluorescence Quenching in Nitrophenyl-Containing Thiazolothiazoles for Efficient Organic Vapor Sensing.

Solvatofluorochromic molecules provide strikingly high fluorescent outputs to monitor a wide range of biological, environmental, or materials-related sensing processes. Here, thiazolo[5,4-d]thiazole (TTz) fluorophores equipped with simple alkylamino and nitrophenyl substituents for solid-state, high-performance chemo-responsive sensing applications are reported. Nitroaromatic substituents are known to strongly quench dye fluorescence, however, the TTz core subtly modulates intramolecular charge transfer (ICT) enabling strong, locally excited-state fluorescence in non-polar conditions.

Spectroelectrochemical and Theoretical Study of [Si(ttpy)](PF): A Potential Polychromatic Electrochromic Dye.

Complexes consisting of earth-abundant main group metals such as silicon with polypyridine ligands are of interest for a variety of optical and electronic applications including as electrochromic colorants. Previous spectroelectrochemical studies with tris(2,2'-bipyridyl)silicon(IV) hexafluorophosphate, [Si(bpy)](PF) demonstrated an ability to control the color saturation of the potential electrochromic dye, with the intensity of the dye's green color increasing as the charge state sequentially reduces from 4+ to 1+. In this study, the synthesis of bis(4'-(4-tolyl)-2,2':6',2″-terpyridine)silicon(IV) hexafluorophosphate, [Si(ttpy)](PF), is reported along with electrochemical and spectroelectrochemical analyses.

II-VI Organic-Inorganic Hybrid Nanostructures with Greatly Enhanced Optoelectronic Properties, Perfectly Ordered Structures, and Shelf Stability of Over 15 Years.

Organic-inorganic hybrids may offer material properties not available from their inorganic components. However, they are typically less stable and disordered. Long-term stability study of the hybrid materials, over the anticipated lifespan of a real-world electronic device, is practically nonexistent.

Accessing new microporous polyspirobifluorenes via a C/Si switch.

Microporous spirosilabifluorene networks were synthesized via Yamamoto coupling of tetrabromospirosilabifluorene precursors. They exhibit bright fluorescence that is quenched in the presence of nitroaromatics. The C/Si switch has subtle effects on the optical properties of the spirobifluorene network and provides a convenient route to 3,3',6,6'-coupled and other polybifluorenes.

Si(bzimpy) - a hexacoordinate silicon pincer complex for electron transport and electroluminescence.

A neutral hexacoordinate silicon complex containing two 2,6-bis(benzimidazol-2'-yl)pyridine (bzimpy) ligands has been synthesized and explored as a potential electron transport layer and electroluminescent layer in organic electronic devices. The air and water stable complex is fluorescent in solution with a λmax = 510 nm and a QY = 57%. Thin films grown via thermal evaporation also fluoresce and possess an average electron mobility of 6.

Spectroelectrochemistry of tris(bipyridyl)silicon(IV): ligand localized reductions with potential electrochromic applications.

Tris(bipyridyl)silicon(iv) was electrochemically reduced in acetonitrile to obtain the UV-vis spectra of its reduced species. Three stable, reversible reduced states (3+, 2+, and 1+) were observed with distinct isosbestic points for each of the redox reactions. The fully oxidized state (4+) is colorless, while the reduced states were green.

Biomolecular screening with encoded porous-silicon photonic crystals.

Strategies to encode or label small particles or beads for use in high-throughput screening and bioassay applications focus on either spatially differentiated, on-chip arrays or random distributions of encoded beads. Attempts to encode large numbers of polymeric, metallic or glass beads in random arrays or in fluid suspension have used a variety of entities to provide coded elements (bits)--fluorescent molecules, molecules with specific vibrational signatures, quantum dots, or discrete metallic layers. Here we report a method for optically encoding micrometre-sized nanostructured particles of porous silicon.