Tetraanionic Oligo-Dioxaborines: Strongly Absorbing Near-Infrared Dyes.

Polymethine dyes of tetraanionic nature comprising 1,3,2-dioxaborine rings in the polymethine chain and end-groups of different electron-accepting abilities have been synthesized. They can be considered as oligomeric polymethines, where a linear conjugated π-system passes through three 1,3,2-dioxaborine units and a number of tri- and dimethine π-bridges between two end-groups. The obtained dyes exhibit near-infrared absorption and fluorescence, with molar absorption coefficients reaching as high as 564000 M cm in DMF, rendering them among the strongest absorbers known.

Trianionic 1,3,2-Dioxaborine-Containing Polymethines: Bright Near-Infrared Fluorophores.

Trianionic polymethines of the A'-π-A-π-A-π-A' type comprising dioxaborine rings (A) and different electron-accepting end groups (A') have been synthesized. The obtained dyes absorb and emit light in the near-infrared region with remarkably high molar attenuation coefficients (ϵ up to 495 000 M  cm in DMF) and fluorescence quantum yields (Φ up to 0.73 in DMF).

Highly Fluorescent Dianionic Polymethines with a 1,3,2-Dioxaborine Core.

The difluoroboron β-diketonate ring is ever more used for creating bright polymethine-type fluorophores for the visible and NIR range. Here, we report the synthesis and spectral properties of a series of dianionic cyanine dyes of the rare A-π-A-π-A type, with the central dioxaborine ring (A) embedded into the polymethine chain and various electron-acceptor terminal groups A. Depending on the nature of the end group, the maxima of their intensive (with molar extinctions up to 380 000 M cm) and narrow long-wavelength absorption band lie in the range of 530-770 nm.

A dioxaborine cyanine dye as a photoluminescence probe for sensing carbon nanotubes.

The unique properties of carbon nanotubes have made them the material of choice for many current and future industrial applications. As a consequence of the increasing development of nanotechnology, carbon nanotubes show potential threat to health and environment. Therefore, development of efficient method for detection of carbon nanotubes is required.

A sensing mechanism for the detection of carbon nanotubes using selective photoluminescent probes based on ionic complexes with organic dyes.

The multifunctional properties of carbon nanotubes (CNTs) make them a powerful platform for unprecedented innovations in a variety of practical applications. As a result of the surging growth of nanotechnology, nanotubes present a potential problem as an environmental pollutant, and as such, an efficient method for their rapid detection must be established. Here, we propose a novel type of ionic sensor complex for detecting CNTs - an organic dye that responds sensitively and selectively to CNTs with a photoluminescent signal.

3,5-Bis(acetaldehyde) substituted BODIPY.

Two versions of a facile and efficient synthetic approach to 3,5-bis(acetaldehyde) substituted BODIPY have been developed and this compound has been used to obtain, in high yields, a variety of 3,5-divinyl BODIPY derivatives (vinylacetates, enamines, vinyl chlorides, and some multiple-functionalized products). As shown, vinyl substituents have an additive effect on the position of the BODIPY absorption maximum. The dyes synthesized are quite stable and exhibit intense absorption and fluorescence with wavelengths longer than 600 nm.

Two-Photon Absorption Spectrum of a Single Crystal Cyanine-like Dye.

The two-photon absorption (2PA) spectrum of an organic single crystal is reported. The crystal is grown by self-nucleation of a subsaturated hot solution of acetonitrile, and is composed of an asymmetrical donor-π-acceptor cyanine-like dye molecule. To our knowledge, this is the first report of the 2PA spectrum of single crystals made from a cyanine-like dye.

Fluorescent labeling of proteins with amine-specific 1,3,2-(2H)-dioxaborine polymethine dye.

A novel water-soluble amine-reactive dioxaborine trimethine dye was synthesized in a good yield and characterized. The potential of the dye as a specific reagent for protein labeling was demonstrated with bovine serum albumin and lysozyme. Its interaction with proteins was studied by fluorescence spectroscopy and gel electrophoresis.

Efficient two-photon absorbing acceptor-pi-acceptor polymethine dyes.

We present an experimental and theoretical investigation of the linear and nonlinear optical properties of a series of acceptor-pi-acceptor symmetrical anionic polymethine dyes with diethylamino-coumarin-dioxaborine terminal groups and different conjugation lengths. Two-photon absorption (2PA) cross sections (delta(2PA)) are enhanced with an increase of pi-conjugation length in the investigated series of dyes. 2PA spectra for all dyes consist of two well-separated bands.