Photochemical Properties and Stability of BODIPY Dyes

Abstract

The present study is devoted to the combined experimental and theoretical description of the photophysical properties and photodegradation of the new boron-dipyrromethene (BODIPY) derivatives obtained recently for biomedical applications, such as bacteria photoinactivation (Piskorz et al., Dyes and Pigments 2020, 178, 108322). Absorption and emission spectra for a wide group of solvents of different properties for the analyzed BODIPY derivatives were investigated in order to verify their suitability for photopharmacological applications. Additionally, the photostability of the analyzed systems were thoroughly determined. The exposition to the UV light was found first to cause the decrease in the most intensive absorption band and the appearance of the hypsochromically shifted band of similar intensity. On the basis of the chromatographic and computational study, this effect was assigned to the detachment of the iodine atoms from the BODIPY core. After longer exposition to UV light, photodegradation occurred, leading to the disappearance of the intensive absorption bands and the emergence of small intensity signals in the strongly blue-shifted range of the spectrum. Since the most intensive bands in original dyes are ascribed to the molecular core bearing the BF2 moiety, this result can be attributed to the significant cleavage of the BF2 ring. In order to fully characterize the obtained molecules, the comprehensive computational chemistry study was performed. The influence of the intermolecular interactions for their absorption in solution was analyzed. The theoretical data entirely support the experimental outcomes.

Non-covalent attachment of BODIPY-caged amines to graphene and their localized photocleavage

“…S14–S20). Similarly to the previous studies of BODIPY dyes, 27–29 NMR studies indicate the photodegradation of the BODIPY core: after irradiation, peaks related to BODIPY core disappeared and new peaks potentially derived from the degradation products arose (ESI,† Fig. S14).…”

Molecular Rotors for In Situ Local Viscosity Mapping in Microfluidic Chips

“…The absorption and emission spectra of BODIPY-2-OH were measured, respectively, using an Agilent Technologies Cary UV−Visible spectrophotometer and an Agilent Technologies Cary Eclipse fluorescence spectrophotometer. BODIPY molecules are susceptible to photodegradation after constant irradiation; 32 this process is slow enough to be negligible over the duration of our experiments, but samples were stored in amber vials to limit bleaching by ambient light. Single-use cuvettes (BRAND GMBH 70 μL UV-Cuvette micro) were used for excitation and emission spectra measurements.…”

Long-Wavelength Absorbing Benzimidazolo-Chlorin for Enhanced Photodynamic Therapy

“…In general, irradiating the tumor site with a suitable wavelength can activate photosensitizers (PSs) that have selectively accumulated in the tumor tissue, causing a photochemical reaction, which results in the necrosis of the tumor tissue. − It can only be applied to shallow tissues due to low penetration and the absorption of surrounding tissues . As a result, a key parameter of ideal PS is the absorption ability of light in the long-wavelength region, where sufficient tissue penetration by PS-activating light, known as the therapeutic window, − can be achieved for overcoming the aforementioned shortcomings, resulting in deeper tumor treatment without side effects.…”