Pyridalthiadiazole acceptor-functionalized triarylboranes with multi-responsive optoelectronic characteristics

Abstract

The functionalization of triarylboranes with pyridalthiadiazole (PT) acceptor moieties gives Ar2B–π–PT dyads and PT–π–B(Ar)–π–PT triads with low-lying PT-centered LUMO orbitals. Addition of a fluoride source results in competing anion binding to boron and PT reduction, depending on the steric and electronic structure of the B-aryl group.

B2N2‐Embedded Polycyclic Aromatic Hydrocarbons with Furan and Thiophene Derivatives Functionalized in Crossed Directions

“…Moreover,t his longer wavelength emission band is solventd ependent and ab athochromic shift of 66 nm can be observed (FigureS4, Supporting Information) when the solvent polarity was increased from cyclohexane (452 nm) to N,N-dimethylformamide (518 nm). Therefore, this longer wavelength emission is characteristicf or an efficient charget ransfer from the boron center with localized negative charge to the neutral conjugated backbone, [26] as also supported by theoretical calculations. Furthermore, the two boron atoms can interact with two fluoride ions to form dianion 2F-BNFS 2À À ,w hichi sv erified by electrochemical characterizations as discussed below.A pproximately 20 equivalents of fluoride ions are required to realize the switching for neutral BNFS to monoanion 1F-BNFS À À and further to dianion 2F-BNFS 2À À .T he emission band at higher energy region continuously decreased while the lower energy ICT band gradually increased in the PL spectra ( Figure 5).…”

“…Moreover, this longer wavelength emission band is solvent dependent and a bathochromic shift of 66 nm can be observed (Figure S4, Supporting Information) when the solvent polarity was increased from cyclohexane (452 nm) to N , N ‐dimethylformamide (518 nm). Therefore, this longer wavelength emission is characteristic for an efficient charge transfer from the boron center with localized negative charge to the neutral conjugated backbone, as also supported by theoretical calculations. Furthermore, the two boron atoms can interact with two fluoride ions to form dianion 2F‐BNFS 2− , which is verified by electrochemical characterizations as discussed below.…”

A simple multi-responsive system based on aldehyde functionalized amino-boranes

“…Donor–acceptor systems have a special place in organoboron chemistry and organoboron-based optoelectronic materials. 9 Manipulating donor–acceptor interactions in boron-based systems has led to non-linear optical materials, 10 anion sensors, 11 charge transport materials for solar cells, 12 emitters for organic light emitting devices (OLEDs), 13 and molecular thermometers. 6e , f Combining a switchable internal donor–acceptor bond with an internal donor–acceptor CT system could allow the creation of new and versatile multi-responsive materials.…”

Triarylborane-Based Materials for OLED Applications

“…Jäkle and co-workers introduced a series of triarylborane compounds 33 – 36 functionalized with a second electron acceptor, pyridyl[2,1,3]thiadiazole ( Figure 7 ) [ 68 ]. These compounds exhibited high stability and were highly photoluminescence (PL) having emission bands in the range of 495 to 535 nm with Φ F values between 32% and 52% in solution.…”

“…They indicated coherent red shift with emission bands appearing between 578 and 622 nm, and compounds 33 and 34 rendered relatively high luminescence quantum yields of 12% and 18% in solid state, respectively. Extension of conjugation in 37 , synthesized via coupling of 33 with 2-hexylthiophene, resulted in higher thermal stability and solubility [ 68 ]. Compound 37 demonstrated strong red-emission at 610 nm with high Φ F of 68%, and an excellent electrochemical reversibility compared to 33 .…”