Excited-state engineering of oligothiophenes via phosphorus chemistry towards strong fluorescent materials

Abstract

Due to the efficient intersystem crossing (ISC), combined with efficient non-radiative processes of the triplet excited state, oligothiophenes generally exhibit very weak photoluminescence. Phosphorus (P)-bridged terthiophenes (P-terThs) and phosphorus (P)-bridged...

Synthesis and Unexpected Optical Properties of Ionic Phosphorus Heterocycles with P-Regulated Noncovalent Interactions

“…For P-OCPs in the literature, the ionic P-center generally induced red-shifted absorption and emission spectra due to either the presence of the ICT state or the decreased HOMO–LUMO gap. ,− According to our previous studies, the structure of 2b is expected to become planar from S 0 to S 1 , presumably due to the intramolecular H-bonding between N H -indole and O (MI). The NMR studies suggested that the N H acidity of 2bMe is stronger than those of 2b , bO (Figure a).…”

“…Since applying P-chemistry, such as oxidation, alkylation, borylation, metal coordination, etc., can fine-tune the photophysical properties of P-OCPs in previous studies, ,,,− we further investigated the effects of oxidation and methylation of the P-center on the photophysical properties (Figure and Table ). Due to the high instability toward oxygen, the photophysical characterizations of 1-3c were not conducted.…”

Stille type P–C coupling polycondensation towards phosphorus-crosslinked polythiophenes with P-regulated photocatalytic hydrogen evolution

“…Compared with those of P1, P2, and P3, 31 P ssNMR spectra of P1Me (5.2 ppm), P2Me (2.6 ppm) and P3Me (1.5 ppm) exhibit clear downfield chemical shifts (Figure 2b), which are consistent with 31 P NMR chemicalshift changes observed in related P(Me)-containing oligothiophenes. 60 Moreover, the observations of the peaks at ca. 79 -80 ppm in 19 F ssNMR spectra (Figure 2c), the peaks at ca.…”

“…2b), which are consistent with 31 P NMR chemical-shi changes observed in related P(Me)-containing oligothiophenes. 60 Moreover, the observations of the peaks at ca. 79-80 ppm in 19 F ssNMR spectra (Fig.…”

Facile Route to Novel Diazaphosphinine‐Based Polycyclic Aromatic Hydrocarbons

“…[11] Furthermore, applying the rich P-chemistry is very effective to tailor the OCMs for specific functionalities. [11,13,[17][18][19] Compared to other P-heterocycle-based OCMs, research of six-membered P-heterocycle derivatives, such as phosphinine (Figure 1), is still in its infancy, largely due to their synthetic challenges and/or instability. [20][21][22][23][24][25][26] Encouragingly, synthetic protocols for accessing phosphinine-based OCMs have been advanced in recent years.…”