Understanding how Lewis acids dope organic semiconductors: a “complex” story

Abstract

We report on computational studies of the potential of three borane Lewis acids (LAs) (B(C6F5)3 (BCF), BF3, and BBr3) to form stable adducts and/or to generate positive polarons with three...

Protonation-induced charge transfer and polaron formation in organic semiconductors doped by Lewis acids

“…We note that the proton positions considered are the second most energetically favorable proton positions according to Marqués et al calculated proton affinities, 15 but the difference in calculated proton affinity is only 4.2 kcal mol −1 compared to their most favorable proton position with the highest proton affinity. Modeled protonated systems with the most favorable proton position result in a 130° twisted backbone, which is a major barrier to the formation of the electronic ground state in experimental environments.…”

“… 14 Theoretical investigations on the protonation pathway propose that a BCF : HO − counter anion energetically disfavors the protonation of PCPDT-BT, but formation of a [BCF : HO : BCF] − or [BCF : HO : H 2 O : BCF] − counter anion open an exergonic pathway and thus favors the protonation. 15 …”

B ← N Coordination Enables Efficient p-Doping in a Pyrazine-Based Polymer Donor Toward Enhanced Photovoltaic Performance

“…−3.0 eV), the ICT doping mechanism is almost impossible in the PBP-Cl/BCF system. Again, another strong evidence to exclude the ICT mechanism is that the absorption of the BCF-doped PBP-Cl shows no signals in the near-infrared (NIR) region until 1100 nm (Figure c), which is a representative feature that occurs in the ICT mechanism. , Recently, Nguyen and Beljonne et al proposed a Brönsted acid mechanism considering the strong adduction tendency of BCF to water. , However, in this work, the BCF was purchased in an anhydrous form, which can be proved by the 11 B NMR spectra. According to the literature, pristine BCF exhibits the B signal at 59 ppm, whereas the B signal of the BCF-H 2 O adduct moves to 6.65 ppm.…”

“…42,43 Recently, Nguyen and Beljonne et al proposed a Bronsted acid mechanism considering the strong adduction tendency of BCF to water. 29,44 However, in this work, the BCF was purchased in an anhydrous form, which can be proved by the 11 B NMR spectra. According to the literature, 45 pristine BCF exhibits the B signal at 59 ppm, whereas the B signal of the BCF-H 2 O adduct moves to 6.65 ppm.…”

Sustainable Approaches to Selective Conversion of Cellulose Into 5-Hydroxymethylfurfural Promoted by Heterogeneous Acid Catalysts: A Review

“…In comparison with Lewis acid catalysis, Lewis acids inhering empty orbits can accept electron pairs in chemical concepts ( Marqués et al, 2021 ). In other words, acidic sites of Lewis acids are capable of being transformed into Brønsted acidic sites by combination with pairs of electrons donated from protic solvent, which can be responsible for the isomerization of glucose into fructose ( Delidovich and Palkovits., 2015 ; Xu et al, 2017 ).…”