Tetrachromophoric Derivatives of Dibenzoylmethanatoboron Difluoride Based on Stereoregular Cyclotetrasiloxanes: Synthesis and Properties.

A series of new tetrachromophoric systems based on stereoregular tetracyclosiloxanes and dibenzoylmethanatoboron difluoride derivatives have been synthesized and characterized by a complex of physicochemical methods. The photophysical properties of the synthesized compounds are studied by electronic absorption, steady-state, and time-resolved fluorescence spectroscopy. In the synthesized compounds, four dibenzoylmethanatoboron difluoride (DBMBF)-based fluorophores are in an all-cis arrangement with respect to a cyclotetrasiloxane scaffold.

Ratiometric Singlet Oxygen Sensor Based on BODIPY-DPA Dyad.

Compounds sensitive to reactive oxygen species are widely used in the study of processes in living cells and in the development of therapeutic agents for photodynamic therapy. In the present work, we have synthesized a dyad in which the BODIPY dye is chemically bound to 9,10-diphenylanthracene (DPA). Here, DPA acts as a specific sensor of singlet oxygen and BODIPY as a reference dye.

Polydimethylsiloxanes with Grafted Dibenzoylmethanatoboron Difluoride: Synthesis and Properties.

A method for the preparation of polydimethylsiloxanes with grafted methoxy-substituted dibenzoylmethanatoboron difluoride has been described. The structures of prepared polymers were confirmed using NMR, IR spectroscopy and gel permeation chromatography methods. Their thermal properties were investigated using thermal gravimetric analysis, differential scanning calorimetry and thermomechanical analysis.

Modulation of Membrane Microviscosity by Protein-Mediated Carotenoid Delivery as Revealed by Time-Resolved Fluorescence Anisotropy.

Carotenoids are potent antioxidants with a wide range of biomedical applications. However, their delivery into human cells is challenging and relatively inefficient. While the use of natural water-soluble carotenoproteins capable to reversibly bind carotenoids and transfer them into membranes is promising, the quantitative estimation of the delivery remains unclear.

The Use of the Thiol-Ene Addition Click Reaction in the Chemistry of Organosilicon Compounds: An Alternative or a Supplement to the Classical Hydrosilylation?

This review presents the main achievements in the use of the thiol-ene reaction in the chemistry of silicones. Works are considered, starting from monomers and ending with materials.The main advantages and disadvantages of this reaction are demonstrated using various examples.

Cross-Linked Luminescent Polymers Based on -Diketone-Modified Polysiloxanes and Organoeuropiumsiloxanes.

Nowadays, luminescent materials attract wide attention due to their valuable characteristics and broad area of potential application. Luminescent silicone-based polymers possess unique properties, such as flexibility, hydrophobicity, thermal and chemical stabilities, etc., which allow them to be utilized in various fields, such as optoelectronics, solid-state lasers, luminescent solar concentrators, sensors, and others.

Tetrahedral Silicon-Centered Dibenzoylmethanatoboron Difluorides: Synthesis, Crystal Structure, and Photophysical Behavior in Solution and the Solid State.

Four tetrahedral silicon-centered derivatives of dibenzoylmethanatoboron difluoride (DBMBF ) were synthesized and characterized. Their structural and optical features both in solution and the solid state were investigated by using X-ray crystallography, steady-state and time-dependent spectroscopy, and DFT-based calculations. In dilute solutions, the molar absorption coefficient increases from 40500 to 175200 M  cm as the number of DBMBF fragments in a molecule increases from one to four, while, in contrast, the nonradiative rate constant of fluorescence decay decreases from 0.

BODIPY-based dye for no-wash live-cell staining and imaging.

In nonpolar solvents, hydrophobic organic fluorophores often show bright fluorescence, whereas in polar media, they usually suffer from aggregation-caused quenching (ACQ). Here, we harnessed this solvatochromic behavior of a 1,3,5,7-tetramethyl-BODIPY derivative for cell staining and applied it to live-cell imaging and flow cytometry. As opposed to commercially available dyes, this BODIPY derivative showed excellent contrast immediately after staining and did not require any wash-off.

Synthesis and photophysical properties of halogenated derivatives of (dibenzoylmethanato)boron difluoride.

A series of (dibenzoylmethanato)boron difluoride (BFDBM) derivatives with a halogen atom in one of the phenyl rings at the para-position were synthesized and used to elucidate the effects of changing the attached halogen atom on the photophysical properties of BFDBM. The room-temperature absorption and fluorescence maxima of fluoro-, chloro-, bromo- and iodo-substituted derivatives of BFDBM in THF are red-shifted by about 2-10nm relative to the corresponding peaks of the parent BFDBM. The fluorescence quantum yields of the halogenated BFDBMs (except the iodinated derivative) are larger than that of the unsubstituted BFDBM.

Synthesis and Antioxidant Activity of 7-Thio Derivatives of 6,7-Dihydro-1H-cyclopenta[d]pyrimidine-2,4(3H,5H)-dione.

New 7-thio derivatives of 6,7-dihydro-1H-cyclopenta[d]pyrimidine-2,4(3H,5H)-dione have been synthesized by the reaction of 3-cyclohexyl-7-thio-6,7-dihydro-1H-cyclopenta[d]pyrimidine-2,4(3H,5H)-dione with alkylhalogenides. The synthesized compounds were tested for antioxidant activity on the model of Fe(2+)-dependent oxidation of adrenaline in vitro. It was found that the antiradical activity of 7-thio derivatives of 6,7-dihydro-1H-cyclopenta[d]pyrimidine-2,4(3H,5H)-dione significantly depends on the structure of the substituent which is part of the thioether fragment of the base molecule.

Gas response behaviour and photochemistry of borondiketonate in acrylic polymer matrices for sensing applications.

The fluorescent spectra in combination with gas response behavior of acrylic polymers doped with dibenzoyl(methanato)boron difluoride (DBMBF2) were studied by fluorescence spectroscopy and time-resolved fluorescence lifetime. The role of acrylic matrix polarity upon the fluorescence spectra and fluorescence lifetime was analyzed. Changes in emission of the dye doped polymers under exposure to toluene, n-hexane and ethanol were monitored.