Ratiometric fluorescence sensing of fluoride ions by triarylborane–phenanthroimidazole conjugates

Triarylboryl‐Functionalized Oxadiazole as a Host Material with Electron Transporting Property for Green PhOLEDs

“…Moreover, the final absorption band after fluoride binding was slightly blue‐shifted. Since fluoride binding to the boron center of 1 may cause the disruption of the extended conjugation through the boron atoms and the central ring planes, the energy level of the π* orbital in the resulting fluoride adduct ([ 1 F 2 ] 2− ) would be elevated, leading to the blue‐shift of the absorption . This finding is in accordance with coplanarity between the ring fragments observed in the crystal structure of 1 .…”

Quinolinol‐based Al/Triarylborane Dyad Assembly: Alteration of Electronic Transition States Mediated by Fluoride Anion Binding

“…The absorption and emission properties of q 2 Al/triarylborane dyads D1 – D3 were investigated with UV/Vis absorption and PL measurements (Figures and Table ) at ambient temperature. All absorption spectra of the dyads in THF (3.0 × 10 −5 M) exhibited major absorption bands in the range of 300–350 nm, which can be assigned to the π(Mes)–p π (B) charge‐transfer (CT) transition in the tri‐coordinated borane moiety (Figure (a)–(c), black line) . The spectra also showed a low‐energy shoulder absorption band in the region above 350 nm, which corresponded to the CT transition from the phenoxy bridge moiety to the q 2 Al parts (for details, refer to the Section “Theoretical Calculations”).…”

“…Among such receptors, triarylborane compounds have received a considerable amount of attention as the most effective molecular platforms due to their excellent Lewis acidities and high selectivity, which is readily controlled by the steric protection of the ortho ‐substituents on the aryl group . As one of the recent research trends in triarylborane‐based chemosensors for detecting fluorides, the introduction of various organic or organometallic luminophores into triarylboranes has been actively exhibited to induce photophysical responses such as a change in the turn‐on and turn‐off signals of those emissive properties that can be observed before and after binding to fluorides . Such a photophysical change in the dyad complexes, which links triarylborane and luminophore together, is generally evoked by the alteration of their intramolecular charge‐transfer (ICT) transition.…”

Design and synthesis of some imidazolyl derivatives: Photophysical studies and application in detection of anions

“…Phenanthroimidazole based systems due to the dramatic supramolecular properties, stability, ease of synthesis, a high extinction coefficient and tuneable photophysical properties have been explored as potential chromophores in a molecular-tweezers system for explosives [45], amine sensors [46,47], fluorophore in a super-radiant laser dye [48], fluorescent tag [49], OLED materials [50][51][52] and chemosensors [53][54][55][56]. The one-step synthesis of phenanthroimidazole derivatives has remarkably increased our own interest to involve a variety of aldehydes that may further extend the way for the introduction of other functionalities and to extend the conjugation for different purposes.…”

“…First, ICT get restricted, due to the formation of a Michael adduct, DCPPI-CNand fluorescence quenching observed at 614 nm. Secondly, the interaction of CNwith second ionophore, the -NH fragment of resultant adduct, DCPPI-CNled to enhance ICT due to an increase in charge density on the phenanthroimidazolyl unit, that finally led to a significant fluorescence enhancement (at 490 nm)[19][20][21][22][23][24][25][26][27][28][29][50][51][52][53][54][55][56][57][58].Moreover, since the changes in optoelectronic behavior of probe in the presence of different anions so rapid it was difficult to obtain a precise kinetic plot. We tried to obtain kinetic plot by the addition of CN -(~20 equiv) to a solution of DCPPI and measured the emission spectra at regular time interval.…”