Design, Synthesis, and Crystallization‐Induced Emission of Boron Difluorides β‐Ketoiminates

Abstract

Scheme2.Side reaction of borond ifluoride b-ketoiminate oxidation.Scheme1.Generalmethodo fsynthesis of boron difluoride b-ketoiminates.

Fluorescent 2‐Hydroxy‐3‐(pyridin‐2‐yl)‐4H‐quinolizin‐4‐ones through Dimerization of Pyridineacetic Acids

“…Simple examples of beta‐diketonates and beta‐ketoimine based dyes often exhibit low FQYs in solutions, but demonstrate high emission in the solid state (Scheme 1). [6,7] Therefore, these dyes are promising as aggregation‐induced emitters (AIE), [8] and cannot be considered as conventional fluorescent dyes. This problem can be overcome by their annulation with conjugated systems, which leads to noticeable fluorescence in solutions [9,10] .…”

2-(4-(Dimethylamino)phenyl)-3,3-difluoro-4,6-diphenyl-3,4-dihydro-1,2,4,5,3-tetrazaborinin-2-ium-3-ide

“…Various boron chelates are some of the most common fluorophores, finding widespread practical application in bioimaging [1], as molecular reporters and chemodosimeters [2,3], in sensors [4][5][6], in optoelectronic applications [7][8][9] and others. The most studied are BODIPY 1 [10][11][12] and their structural analogs 2 [13], BOPHY 3 [14], boron difluoride 1,3-diketonates 4 [15] and 1,3-ketoiminates 5 [16]. Difluoroboron derivatives of different types of hydrazones 6 [17], such as N-acylhydrazones 7 [18] and azohydrazones (formazanes) 8 [19] (Figure 1), are also of interest and are being extensively studied at the present time.…”