Photophysical and anion sensing properties of a triphenylamine–dioxaborinine trimeric compound

Abstract

The one-pot triphenylamine functionalization with multiple dioxaborinine groups gives the novel dye A2 with two-photon absorption and cyanide-sensing properties. The solvatofluorochromism of A2 was interpreted in terms of solvent dipolarity.

Pyrazolo[1,5‐a]pyrimidine‐Dioxaborinine Hybrid Dyes: Synthesis and Substituent Effect in the Photophysical Properties

“…Remember that fluorophores containing dioxaborinine core have been widely reported; [5–12,26,32–34] nevertheless, those bearing the pyrazolo[1,5‐ a ]pyrimidine ring are rare, although some interesting examples have been reported in our research group [16,17,22,29,35,36] . Fluorophores of extended π‐conjugation ( Py‐DB , R 2 ‐DB , and TPA‐DB 3 ) and with various substitutions such as phenyl ( Ph 2 ‐DB ), methoxyaryl ( Py‐DB , R 2 ‐DB , and Ar‐PP ), TPA ( TPA‐DB , TPA‐DB 3 , and TPA‐PP ), and coumarin ( Cum‐DB ) groups were used in this analysis.…”

“…498/532 98500 1300 65 DCM [À À ], Suhasini et al [30] 430/527 -4300 49 DMF [À À ], Haucke et al [34] 366/397 40700 2100 39 Toluene [20], Yang et al [32] 379/468 18000 5000 77 CyH [3], Tigreros et al [35] 502/570 129000 2400 61 DCM [1], Chaicham et al [33] 353/479 5100 7500 44 DCM [10], Castillo et al [36] 449/531 87100 3300 85 CHCl 3 [10], Tigreros et al [12] 347/477 17700 7900 69 THF [20], This work 386/454 40700 3900 93 DMSO [20], Wang et al [26] [a] If no information is reported by the authors in the respective work, we assume that such dyes are obtained starting from commercial substrates. distribution throughout the molecule due to the high πconjugation in this compound (Figure 2a).…”

“…We recently got a TPA‐(DB) 3 trimeric fluorophore through a similar method but using a simpler substrate (i.e., free triphenylamine). The synthesis implied the formation of twelve new bonds in a one‐pot manner [12] …”

“…[4] Remarkably, the boron β-diketone difluoride complexes, known as dioxaborinine (DB), have been extensively studied due to their relevant photophysical properties [5] such as significant molar absorption coefficients, [6] size-dependent luminescence, [7] mechanofluorochromism, [8] two-photon absorption activity, [9] controllable emission wavelength by polymeric matrices, [10] and large fluorescence quantum yields. Some DB derivatives have uses in amines [11] or cyanide [12] sensing, bioimaging (cells, tissues, and in vivo), [5] and electroluminescence devices (OLED). [13] Pyrazolo[1,5-a]pyrimidine (PP) derivatives are another attractive class of organic fluorophores with high synthetic versatility and exceptional biological properties.…”

“…[14,15] These dyes have been fascinating in the last few years due to their high fluorescence quantum yields in both solution and solid-phase and excellent photostability, [16,17] which showed great applications mainly as fluorescent chemosensors [17,18] or biomarkers. [19] On the other hand, the π-extended conjugation and the electronic coupling between fluorophores such as triphenyl-amine TPA-fluorene, [20] TPA-BODIPY, [21] TPA-PP, [22] TPA-DB, [12] or pyrene-BODIPY, [23] has allowed the improvement of the optical properties or induce new ones such as solvatofluorochromism, Near Infrared II two-photon absorption, [24] or FRET. [25] Consequently, combining two or more fluorophores is a good strategy for designing dyes with exceptional photophysical properties (Scheme 1).…”