Carboxyl BODIPY Dyes from Bicarboxylic Anhydrides: One-Pot Preparation, Spectral Properties, Photostability, and Biolabeling

Abstract

New fluorescent dyes based on 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) and functionalized with a free carboxyl group have been conveniently synthesized from pyrroles and dicarboxylic anhydrides in one-pot reactions. Their spectral properties in different solvents showed little effect of solvatochromism (<10 nm). The methyl groups on the BODIPY skeleton benefit the fluorescence quantum yields (Phi(f) up to 0.80 in water) but affect the photostability of the dyes. Photooxidation and photodegradation experiments suggest that dyes 1a and 2a exhibit excellent photostability, especially in water, and several factors were taken into account to elucidate the experimental phenomena. Dyes 1c and 2c, derived from 1a and 2a via the esterification of NHS (N-hydroxysuccinimidyl ester), can be easily acquired in high yields (>90%). Single crystal X-ray structures of dyes 2c and 3a are also obtained and discussed. The fluorescence labeling of BSA and followed prestaining method for gel electrophoresis of BSA demonstrate that the protein can be directly observed by naked eyes at as low as 2 ng level under a normal UV fluorescence electrophorogram gel image system.

New luminophors based on the binuclear helicates of d-METALS with BIS(DIPYRRIN)S

“…Bis(dipyrrin)s are the open-chain tetrapyrrolic ligands (H 2 L), which are constructed from two chromophore dipyrrin domains linked by spacer at the 2,2'-, 2,3'-or 3,3'-positions of proximal pyrroles (8)(9)(10) in Fig. 4).…”

“…1) have emerged as a fascinating class of dyes with excellent performance and stability. Thereby, these compounds have found application in sensing, labelling, light-harvesting technologies and photodynamic therapy [2][3][4][5][6][7][8][9][10][11]. For a long time it was considered that homoleptic dipyrrinato metal complexes were incapable to fluorescence, in contrast to their highly fluorescent boron-dipyrrinato analogues.…”

Difluoroboranyl derivatives as efficient panchromatic photoinitiators in radical polymerization reactions

“…Furthermore, laser flash photolysis experiments showed the excited singlet state of the difluoroboranyls may undergo intersystem crossing to give the excited triplet state ( 3 PI). 3 PI interacts with borate salt to produce reactive species. Rate constants (k q ) for the quenching of the excited states of the dyes were low, below diffusion controlled limits and they were dependent on the heterocyclic ring in the sensitizer molecule.…”

“…They are usually characterized by: (a) high extinction coefficient, (b) high fluorescence quantum yield, (c) narrow emission band, (d) relatively long excited-state lifetime, (e) great photostability and (f) large two-photon absorption cross-section [1][2][3]. The photophysical and photochemical properties of the fluorescent difluoroboranyl dyes can be easily modified, e.g.…”

Aggregation induced emission (AIE) active β-ketoiminate boron complexes: Synthesis, photophysical and electrochemical properties

“…Boron complexes, mainly boron dipyrromethene (BODIPY) dyes [6][7][8][9] are the most important types of fluorescent dyes due to their outstanding optical properties such as, high fluorescence quantum yields, extinction coefficients, sharp absorption and fluorescence emission spectra. BODIPY dyes are extensively used as a chemosensors [10][11][12][13][14][15][16], in the biolabeling [17,18], in dye-sensitized solar cells [19,20] and photodynamic therapy [21,22]. However, their use as an electroluminescent material is restricted due to their small stokes shifts which leads to self-quenching [23,24].…”