Supramolecular Diiodine-Bromostannate(IV) Complexes: Narrow Bandgap Semiconductors

Three supramolecular bromostannates(IV) with “trapped” diiodine molecules, Cat₂{[SnBr₆](I₂)} (Cat = Me₄N⁺ (1), 1-MePy⁺ (2) and 4-MePyH (3)), were synthesized. In all cases, I₂ linkers are connected with bromide ligands via halogen···halogen non-covalent interactions. Articles 1–3 were studied using Raman spectroscopy, thermogravimetric analysis, and diffuse reflectance spectroscopy. The latter indicates that 1–3 are narrow band gap semiconductors.     

Oxochloroselenate(IV) with Incorporated {Cl2}: The Case of Strong Cl⋅⋅⋅Cl Halogen Bonding

Reaction of SeO₂, tetramethylammonium (TMA) chloride, aqueous HCl and Cl₂ yields oxochloroselenate with incorporated Cl₂ units, TMA₃{[Se₂O₂Cl₇](Cl₂)}. The main feature of this compound is the strong (up to 3.5 kcal mol⁻¹, according to DFT calculations) Cl⋅⋅⋅Cl bonding, which is also detected by Raman spectroscopy.     

Oxophosphoryl Complexes of Dipyrrin: Spectral and Aggregation Characteristics of Solutions and Thin Films

Crystallography Reports - The spectral characteristics of a compound representing a new class of organic luminescent materials—dipyrrin oxophosphoryl complex (PODIPY)—in organic...     

Opening the Third Century of Polyhalide Chemistry: Thermally Stable Complex with “Trapped” Dichlorine

Unlike polyhalides of heavier halogens, polychlorides still remain exotic curiosities. Herein, we report preparation and investigation of complexes Cat₂{[TeCl₆](Cl₂)} (cat=1-methylpyridinium ( 1 ) and tetramethylammonium ( 2 )) where dichlorine units are “trapped” by chlorotellurate(IV) anions via a system of non-covalent Cl⋅⋅⋅Cl interactions. Complex 2 reveals a record thermal stability (>100 °C) for inclusion compounds with Cl₂, indications that such compounds can be used as solid Cl₂ source.     

On the Percolation Regime of the Bulk Transport of the Bi1.08Sn0.02Sb0.9Te2S Topological Insulator

JETP Letters - The formation of nanosized charge droplets in the bulk of a three-dimensional topological insulator Bi1.08Sn0.02Sb0.9Te2S was evidenced using electron spin resonance. Since electrons...     

One-Dimensional Iodoantimonate(III) and Iodobismuthate(III) Supramolecular Hybrids with Diiodine: Structural Features,Stability and Optical Properties

Two isostructural pairs of supramolecular iodoantimonate(III) and iodobismuthate(III) complexes with I₂ units “trapped” in solid state via halogen bonding—Cat₃[[M₂I₉](I₂)} (Cat = tetramethylammonium and 1-methylpyridinium, M = Sb(III) and Bi(III)) were prepared. For all compounds, values of optical band gaps were determined, together with thermal stability; the complexes were additionally characterized by Raman spectroscopy.     

Evolution of the active species of homogeneous Ru hydrodeoxygenation catalysts in ionic liquids

This work establishes structure–property relationships in Ru-based catalytic systems for selective hydrodeoxygenation of ketones to alkenes by combining extensive catalytic testing, in situ X-ray absorption spectroscopy (XAS) under high pressures and temperatures and ex situ XAS structural characterization supported by density functional theory (DFT) calculations. Catalytic tests revealed the difference in hydrogenation selectivity for ketones (exemplified by acetone) or alkenes (exemplified by propene) upon changing the reaction conditions, more specifically in the presence of CO during a pretreatment step. XAS data demonstrated the evolution of the local ruthenium structure with different amounts of Cl/Br and CO ligands. In addition, in the absence of CO, the catalyst was reduced to Ru⁰, and this was associated with a significant decrease of the selectivity for ketone hydrogenation. For the Ru–bromide carbonyl complex, selectivity towards acetone hydrogenation over propene hydrogenation was explained on the basis of different relative energies of the first intermediate states of each reaction. These results give a complete understanding of the evolution of the Ru species, used for the catalytic valorization of biobased polyols to olefins in ionic liquids, identifying the undesired deactivation routes as well as possibilities for reactivation.

This work establishes structure–property relationships in Ru-based catalytic systems for the selective hydrodeoxygenation of ketones to alkenes.     

Bodipy Based Fluorescent Materials in Cellulose Matrices: Synthesis,Spectral Properties and Vapochromic Fluorescent Recognition of Alcohols and Acetone

This paper highlights advances made using the 4-bora-3a,4a-diaza-s-indacene (BODIPY) as a fluorophore in design and application of fluorescent sensors for microenvironment polarity. Sections of the paper cover broad analysis of a range of fluorescent indicators immobilized in ethyl- and methyl cellulose matrices. The present study demonstrates that BODIPY-based fluorescent materials could be successfully utilized for ratiometric detection of ethanol and acetone in gas phase. The achieved limit of detection value equals 0.02 mg/ml for acetone and 0.08 mg/ml for ethanol, whereas obtained sensoric materials are reusable without regeneration required.

     

Tetra- and Pentanuclear Iodobismuthates with the Cation Based on 2,3,5,6-Tetramethylpyrazine: Syntheses and Crystal Structures

Russian Journal of Coordination Chemistry - Complexes (HTMP)4[Bi4I16] · 2H2O · 2(CH3)2CO (I) and (HTMP)3[Bi5I18] · 5THF (II) have been synthesized by the reactions of BiI3 and...