Electronic and steric properties of stable silylene ligands in metal(0) carbonyl complexes

A series of stable silylene-transition metal complexes have been synthesized by substitution of silylenes 1 and 2 for carbonyl ligands in simple metal carbonyl complexes: M(1)2(CO)4 and M(2)2(CO)4 (M=Cr, Mo, W), Fe(1)(CO)4 and Ru(1)2(CO)3. X-ray crystal structures are reported. Infrared and NMR spectroscopy were used to probe the electronic properties of stable silylene ligands. Based on these data, the stable silylene 1 behaves electronically very much like triaryl phosphines. © 2001 Elsevier Science B.V

Optical dielectric function of Si(2,6-bis(benzimidazol-2 -yl)pyridine)(2) determined by spectroscopic ellipsometry

Si(bzimpy)(2), a fluorescent organic complex, has been demonstrated as a potential electron transport and electroluminescent layer for organic electronic devices. Despite the successful synthesis and encouraging electroluminescence at 560 nm, the complex dielectric function of the water-stable complex has not been reported yet. In this letter, we report on the first spectroscopic ellipsometry data obtained from a Si(bzimpy)(2) thin film in the spectral range from 300 nm to 1900 nm (0.65 eV to 4.1 eV). A parameterized model dielectric function composed of a Tauc-Lorentz and Gaussian oscillators is employed to analyze the experimental ellipsometry data. We find a good agreement between the absorption energies observed experimentally here and density functional theory calculations reported earlier.Funding Agencies|NSF within the I/UCRC Center for Metamaterials [1624572]; NSF \ MPS \ Division of Chemistry (CHE) [CHE-1800331]; Swedish Agency for Innovation Systems [2014-04712]; NanoSURE program [CHE-1460867]</p

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

Abstract 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. In polar media, a planar ICT excited‐state shows near complete quenching, enabling a twisted excited‐state emission to be observed. These unique fluorescent properties (spectral shifts of 0.13 – 0.87 eV and large transition dipole moments Δµ = 20.4 – 21.3 D) are leveraged to develop highly sought‐after chemo‐responsive, organic vapor optical sensors. The sensors are developed by embedding the TTz fluorophores within a poly(styrene‐isoprene‐styrene) block copolymer to form fluorescent dye/polymer composites (ΦF = 70 – 97%). The composites respond reversibly to a comprehensive list of organic solvents and show low vapor concentration sensing (e.g., 0.04% solvent saturation vapor pressure of THF – 66 ppm). The composite films can distinguish between solvent vapors with near complete fluorescent quenching observed when exposed to their saturated solvent vapor pressures, making this an extremely promising material for optical chemo‐responsive sensing

CCDC 2109550: Experimental Crystal Structure Determination

Related Article: Adam W. Earnhardt, Kevin Boyle, Tyler Adams, Michael G. Walter, Yizhou Wang, Yong Zhang, Adesola Adeyemi, Jon Merkert, Askhat N. Bimukhanov, Anuar A. Aldongarov, Colin D. McMillen, Thomas A. Schmedake|2021|J.Organomet.Chem.|961|122208|doi:10.1016/j.jorganchem.2021.12220

CCDC 2109551: Experimental Crystal Structure Determination

Related Article: Adam W. Earnhardt, Kevin Boyle, Tyler Adams, Michael G. Walter, Yizhou Wang, Yong Zhang, Adesola Adeyemi, Jon Merkert, Askhat N. Bimukhanov, Anuar A. Aldongarov, Colin D. McMillen, Thomas A. Schmedake|2021|J.Organomet.Chem.|961|122208|doi:10.1016/j.jorganchem.2021.12220

CCDC 2109552: Experimental Crystal Structure Determination

Related Article: Adam W. Earnhardt, Kevin Boyle, Tyler Adams, Michael G. Walter, Yizhou Wang, Yong Zhang, Adesola Adeyemi, Jon Merkert, Askhat N. Bimukhanov, Anuar A. Aldongarov, Colin D. McMillen, Thomas A. Schmedake|2021|J.Organomet.Chem.|961|122208|doi:10.1016/j.jorganchem.2021.12220