Display omitted
•New CH(Ar)-bis(BODIPY)s were synthesized;•The CH(Ar)-bis(BODIPY)s are characterized by conformational mobility;•The CH(Ar)-bis(BODIPY)s are highly sensitive to the environment ...nature;•The CH(MeOPh)-bis(BODIPY) 3 is the most sensitive towards medium microviscosity;•Dye 3 is promising as a fluorescent sensor of environment local polarity and viscosity.
In this article, we present synthesis, spectral characteristics, and results of DFT calculations of new CH(R)-bis(BODIPY) 1–3. They are characterized by the conformational mobility and sensitivity of fluorescence to polarity, proton-, electron donor ability and viscosity of the solvation environment. It is shown that fluorescence intensity of 1–3 increases in the homologous series of alcohols (ethanol, 1-propanol, 1-butanol, 1-octanol, 1-decanol) mainly due to decrease of medium acidic properties. The viscosity of the medium effects on the 1–3 fluorescence in a lesser degree. Compared to 1 and 2, the 3 is the most sensitive towards viscosity both in low-viscosity homologous alcohols and in high-viscosity ethanol-glycerol mixtures. In this regard, the sensitivity of fluorescence of CH(MeOPh)-bis(BODIPY) (compound 3) to the viscosity was studied in binary mixtures of polar DMF and low-polarity toluene with castor and vaseline oils, as well as to the macroviscosity of the solvate environment in mixtures of toluene with polystyrene. Prospects of the practical application of CH(R)-bis(BODIPY)s are proposed for the analysis of polarity, proton-donor properties and viscosity of the medium.
Display omitted
Red-emitting distyryl substituted BODIPY dyes are among the most promising luminophors for bioimaging and optics applications. However, the practical application of BODIPYs is limited ...due to their high hydrophobicity and tendency to aggregate in aqueous organic solutions and solid phase. In this article, we propose an elegant solution to this problem. To this end, we carried out the detailed experimental and quantum-chemical study of the structural and spectral features of BF2-ms-phenyl-5,5′-bis(4-dimethylaminostyryl)-3,3′-dimethyl-2,2′-dipyrromethene (distyryl-BDP). The particular attention was paid to analysis of high sensitivity of the distyryl-BDP spectral characteristics to the solvent properties, and also the aggregation behavior features both in water-organic media and in mono- and multilayer Langmuir-Schaefer films. We selected the best conditions to obtain the hydrophilic micellar structures of distyryl-BDP with Pluronic® F127 having a high efficiency of dye solubilization. This method increasing the solubility improves the distyryl-BDP transport efficiency in physiological aqueous media. The aqueous solutions of distyryl-BDP–Pl micelles show the intense fluorescence in the phototherapy window region (λfl = 739 nm).
The review highlights recent advances devoted to new luminophores based on d-metal complexes of bis(dipyrrin)s of M2L2. The M2L2 helicates possess intense absorption in a visible spectrum region. The ...Zn2L2, Cd2L2 and Hg2L2 helicates are fluorophores with the most intense fluorescence in nonpolar solvents. The fluorescence of M2L2 bis(dipyrrinate)s decreases by two-fold in aromatic solvents and becomes close to zero in electron-donor media. The fluorescence is increased in a series of 2,2′-, 2,3′-, 3,3′-bis(dipyrrinate)s with similar complexing agent and in a series of Hg2L2, Cd2L2, Zn2L2 complexes with the same ligand. Upon freezing and cooling of Zn2L2 in ethanol from 300 to 77 K the fluorescence quantum yield of Zn2L2 is increased up to 100 times. The Zn2L2 complexes are able to generate the stimulated emission induced at the 550–560 nm region in nonpolar solvents upon excitation by second harmonic Nd:YAG laser.
Display omitted
•Dinuclear homoleptic M2L2 bis(dipyrrin) helicates exhibit intense absorption.•The Zn(II), Cd(II) and Hg(II) bis(dipyrrinate)s give intense fluorescence.•The fluorescence of M2L2 helicates is decreased with increasing of solvent polarity.•Upon cooling of Zn2L2 in ethanol the fluorescence is increased up to 100 times.•In nonpolar media Zn2L2 helicates generate stimulated emission.
Display omitted
•The new mono-Br-substituted BODIPYs were synthesized and characterized;•Spectral characteristics weakly depend on the bromine atom position in the BDP molecule;•The Br-BDPs have ...optimal combination of high fluorescence efficiency and 1O2 generation;•The β-Br-BDPs is more photostable than (β-Br)2-BDP.•Optimal conditions for the host–guest encapsulation of β-Br-BDP in zeolitic imidazolate framework (ZIF-8) are selected.
The development of bifunctional theranostic agents based on biocompatible organic luminophores is a priority for the scientific community. We have obtained new mono-Br-substituted BODIPYs (Br-BDPs) with an optimal combination of fluorescence quantum yield (0.48 ÷ 0.63) and singlet oxygen generation quantum yield (0.32 ÷ 0.51) in different nature solvents. A detailed analysis of the structure of α-Br-BDP, β-Br-BDP, and β'-Br-BDP dyes, their spectral properties depending on the position of the bromine atom attachment and the solvent nature, as well as the aggregation behavior of the dyes in water/THF solvent mixture are presented. We also selected the conditions for the host–guest encapsulation of β-Br-BDP in zeolitic imidazolate framework (ZIF-8). The resulting nanoscale β-Br-BDP@ZIF-8 delivery systems exhibit intense fluorescence. The release of the β-Br-BDP luminophore from the β-Br-BDP@ZIF-8 systems into model lipid structures in phosphate buffer pH 5.0 – 6.0 occurs on average after 24 – 50 h. These results form the basis for the further development of new theranostic drugs based on Br-BDP luminophores for fluorescence diagnostics (FD) and photodynamic therapy (PDT).
It is well known that boron-dipyrromethene (BODIPY) dyes have a remarkable combination of photophysical and photochemical properties, which are significant for practical use. Unfortunately, the ...application of BODIPYs in optical devices and biosensorics is severely limited due to the aggregation quenching effect (ACQ), the effects of the internal filter and/or the formation of excimers. One way to prevent fluorescence quenching is to synthesize new molecules BODIPY with a highly complicated structural organization or hybrid systems based on them. But in this paper, we demonstrate that the introduction of simple aliphatic or aryl substituents into the ms-position of the BODIPY molecule is an effective way to control the aggregation in various states: thin mono- and multilayer Langmuir-Schaefer (LS) films, polymer films and concentrated solutions, including aqueous ones. The results of experimental studies of the aggregation behavior of BODIPYs (BDP1-BDP3) are in good agreement with the theoretical calculations data of di- and tetramers, as well as multilayer packing. This allows to adjust the spectral properties of luminophores to the most possible types of their real applications in practical areas.
Display omitted
•A comparative analysis of the different ms-substituted BODIPYs aggregation behavior in different states was carried out.•The nature of the BODIPY substituent in the ms-position determines the type of dye aggregation in solutions and in the solid phase.•The BDP2 with an extended ester group at the ms-position is distinguished by a significantly lower tendency to aggregation.
The crystal structure and spectral properties of new Zn(ii) chelate complex with bis(2,4,7,8,9-pentamethyldipyrrolylmethen-3-yl)methane were determined by single-crystal X-ray diffraction,
1H NMR, UV ...and IR spectroscopy; a sufficiently high quantum yield of fluorescence in nonpolar solvents, a long-wavelength emission maximum and good photostability of the complex were demonstrated.
Display omitted
•The bis(BODIPY)s fluorescence sensitivity to the medium polarity and acidity was analysed.•The bis(BODIPY)s fluorescence quenching was observed in alcohols.•Bis(BODIPY)s form ...supramolecular complexes with alcohol molecules.•Bichromophoric dyes have prospects of application as alcohols fluorescent sensors.
In this paper, detailed comparative analysis of the spectral properties of bis(BODIPY) dyes in various organic solvents: saturated aromatic hydrocarbons, homologous series of alcohols (CnOH, n = 2–4, 8, 10) and mixture of ethanol-glycerol with different viscosity was carried out. In bis(BODIPY) dimeric molecules, the BODIPY chromophore domains are linked by a methylene spacer at the 2,2-, 2,3-, or 3,3-positions (1, 2, and 3 respectively). The absorption spectra of the bis(BODIPY)s exhibit exciton splitting of band maxima. We showed that bis(BODIPY)s are sensitive to the polarity and acidity of media due to its structural features. The mechanism of fluorescence quenching of 1–3 in the series of alcohols are explained in detail. It has been established that the fluorescence quenching efficiency of dimeric dyes in alcohols is determined by both universal and specific interactions. The fluorescence quantum yield of bis(BODIPY)s is minimal in ethanol and increases in the alcohols homologous series due to a reduction in medium polarity and the stability of the bis(BODIPY)(Solv)2 supramolecular structures. In viscous ethanol-glycerol mixtures, fluorescence of 1–3 increases because of the limitation of the dye molecules conformational mobility. The results of the study allow us to predict the possibility of practical application of 1–3 as alcohols fluorescent sensors in various media.
Photosensitizers (PS) with optimal photophysical characteristics are necessary for an integrated approach to the diagnosis and treatment of diseases various types using photodynamic therapy (PDT). ...This study explores the potential of СН(R)-bis(BODIPY) dyes 1–4, 3a, and 3b as heavy-atom-free рhotosensitizers. A detailed computer study of СН(R)-bis(BODIPY) dyes demonstrates the role of SOCT-ISC (photoinduced spin–orbital charge transfer enhanced ISC) in the 4,4-CH2-bis(BODIPY) 4 photosensitizing properties implementation. The design strategies of a novel water-soluble polymer nanophotosensitizes 4-NPs, based on a dimeric dye 4 and a biocompatible amphiphilic block copolymer Pluronic® F127 are presented. A comparative analysis of dye 4 solubilization efficiency and its spectral properties in the composition of supramolecular 4-NP systems obtained by different techniques, as well as the sizes of the resulting nanostructures, was carried out.
Display omitted
•The potential of CH(R)-bis(BODIPY)s as heavy-atom-free рhotosensitizers have been analyzed.•The role of SOCT-ISC is crucial in realizing photosensitizing properties of 4.•The design strategies of the 4 encapsulation in Pluronic® F127 micelles are presented.•Water-soluble polymer 4-NPs with optimal characteristics have been obtained.
