Dibenzoylmethanatoboron difluoride (DBMBF₂) is a fluorophore capable of forming exciplexes with benzene and its derivatives in solutions [1] or in the adsorbed state on the silica gel surface by reacting with vapor of these substances [2, 3], a property that may be used for the fabrication of highly selective and responsive sensor devices. In this study, the dependence of the fluorescence spectra of silica-supported DBMBF2 samples on the vapor concentration of the aromatic compounds benzene, toluene, and p-xylene has been examined. A model describing the observed spectral changes has been proposed. The data on the concentration dependence of the fluorescence spectra of silica gel microspheres bearing adsorbed DBMBF₂ are in good agreement with the proposed model.

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. In the present work, a metal-ligand interaction approach was applied to obtain new cross-linked luminescent polymers based on multiligand polysiloxanes with grafted β-diketone fragments and organoeuropiumsiloxanes containing various organic substituents. Organoeuropiumsiloxanes were utilized as a source of Eu³⁺ ions due to their compatibility with the silicon matrix. All synthesized polymers were fully characterized and their physicochemical, mechanical, self-healing, optical, and thermal properties were studied.

A new pentafluorinated derivative of (dibenzoylmethanato)boron difluoride (5F-DBMBF₂) was synthesized and studied as an “off–on” fluorescent probe for benzene derivatives with a reversible detection capability. The structure and optical properties of the DBMBF₂ derivative with one pentafluorinated phenyl group were studied by X-ray single-crystal measurements, steady-state UV-visible spectroscopy and computational modeling. 5F-DBMBF₂ is non-planar in the ground state, the fluorinated phenyl ring and dioxaborine heterocycle are inclined at an angle of 30° relative to each other. 5F-DBMBF₂ shows no detectable fluorescence in non-aromatic solvents, but exhibits exciplex emission in the presence of benzene, chlorobenzene, toluene, o- and m-xylenes with considerable red-shifted maxima as compared with corresponding exciplexes of the parent unsubstituted DBMBF₂. DFT calculations predict that the geometric rearrangements during the exciplex formation from a van der Waals complex of 5F-DBMBF₂ with benzene in the ground state involve rotating the perfluorinated phenyl ring by about 10°, shortening of the C–C bond between the phenyl and dioxaborine rings, and a decrease in the average interplanar distance between 5F-DBMBF₂ and benzene molecules by about 0.7 Å.

Silica nanoparticles (SNPs) with a diameter of 100 nm and surface-modified by covalently linked dibenzoylmethanatoboron difluoride have been synthesized and characterized. Suspensions of SNPs in...