Doping Polycyclic Aromatics with Boron for Superior Performance in Materials Science and Catalysis

Abstract

Boron has one valence electron less than ac arbon atom and an availablev acant p z orbital. The incorporation of sp 2 -hybridized boron atoms into the host lattice of ap olycyclic aromatic hydrocarbon (PAH) is formally relatedt oo xidative doping. Ab oron-containing B-PAH has an energetically low-lying LUMO and an arrow HOMO-LUMOg ap, which renders it as trong Lewis acid/electron acceptora nd promotes fluorescencei nt he visible range of the electromagnetic spectrum. Many methods have been developed to access B-PAHs that are deliberately designed for specific tasks. Herein, we highlight recentb reakthroughs in the field of B-PAH synthesis and the scope of their applications, which range from Lewis acid and redox catalysis to device fabrication.W ew illa lso report on the dynamic covalent chemistry of neutral and anionic B-PAHs, as it is ap otential limitationi nt he design of catalysts ystems but can also provide ap owerful synthetic tool for the preparation of otherwise inaccessible B-PAHs.

Intramolecular Borylation via Sequential B−Mes Bond Cleavage for the Divergent Synthesis of B,N,B‐Doped Benzo[4]helicenes

“…Despite their great application potential, for example, in organic optoelectronics, chemical sensing, and organocatalysis, systematic investigation of B‐PAHs is hampered by complex synthetic methods, especially for implementation of multiple boron centers into one molecule . Synthesis of B‐PAHs typically relies on transmetallation and/or electrophilic aromatic substitution involving a strong electrophile (BCl 3 , BBr 3 ), also referred to as Friedel–Crafts (FC) borylation . Lewis acids, for example, AlCl 3 , in combination with a bulky amine NR 3 can activate the electrophile by formation of borenium ions [R 3 N‐BX 2 ] + .…”

A Quadrupolar Bis‐Triarylborane Chromophore as a Fluorimetric and Chirooptic Probe for Simultaneous and Selective Sensing of DNA, RNA and Proteins

“…[3] Given that only af ew examples of water-soluble triarylboranes have been reported to date, [4][5][6][7][8][9][10][11][12][13] such borane-based chromophores could be considered to be novel fluorophores for biochemical applications;t hey are already widely used in nonlinearo ptical materials, organic electronics, organic lightemitting diodes or anion sensors. [14][15][16][17][18][19][20][21][22] However,f luorescence of 1 only enabled intracellularl ocalisation of ad ye, but did not allow fort he determination of at argeted biomacromolecule (for example, protein or DNA or RNA). The question arose as to whether it is possible, by detailed analysis of the dye's spectrophotometric response in ac ell, to determine the type of targeted biomacromolecule,w hich would help to determine the bindings ite and suggest furtherd ye applicationsa nd developments.…”

Polymorphism and pseudosymmetry of 10,10′-oxybis(9-thia-10-hydro-10-boraanthracene)

“…The properties of these all-carbon compounds can be further improved by substitutional doping with main-group elements, which has long been known for elements such as nitrogen, phosphorous, or sulfur (Stę pień et al, 2017). However, only a few boron-doped PAHs have been synthesized to date, mainly because of synthetic difficulties (von Grotthuss et al, 2018).…”