1,2‐Azaborine Cations

Abstract

Positively brilliant: The first examples of 1,2‐azaborine cations have been prepared and their structure and optoelectronic properties characterized (see picture). 1,2‐Azaborine cations exhibit solid‐state fluorescence that is distinct from their neutral all‐carbon analogues, and the 1,2‐azaborine moiety is a critical component for the optoelectronic properties. There is a potential for the utility of these complexes in materials applications.

Fundamental and Applied Properties of Borocations

“…More recently, 1,2-azaborine-containing borenium cations, 36 (Fig. 26), have been synthesised that are emissive in the solid state with high quantum yields and narrow emission bands [43]. A subporphyrin borenium cation, 37, has also been isolated indicating the viability of these species as intermediates in facile boron axial ligand exchange in this class of porphyrinic pigments [104].…”

“…7) [13,17,43,44]. Thus borenium cations can also be considered as masked borinium cations provided they dissociate L at some point during the reaction with a nucleophile.…”

Photoisomerization of 1,2‐Dihydro‐1,2‐Azaborine: A Matrix Isolation Study

“…For example, 1 readily undergoes nucleophilic aromatic substitution reactions under mild reaction conditions [12] and cationic 1,2-azaborines have recently been synthesized by Liu and co-workers. [13] To the best of our knowledge, the photochemistry of 1,2-dihydro-1,2-azaborines has never been investigated.…”

Protecting Group-Free Synthesis of 1,2-Azaborines: A Simple Approach to the Construction of BN-Benzenoids

“…In particular, the relatively short boron-nitrogen (1.412(3) Å) and boron-carbon distances (1.496(3) Å) are shorter than those in a typical B –alkoxide substituted 1,2-azaborine (B–N = 1.436(2) Å, B–C = 1.518(2) Å) 15 and on par with those exhibited by 1,2-azaborine borenium cations (e.g., for Ph 3 P=O adduct: B–N = 1.420(3)- Å, B–C = 1.496(3) Å). 24 The exocyclic oxygen atom O(1) of 14 is mostly sp 2 - hybridized, with ∠B-O(1)-C(7) = 127.4(1)°. The C(7)-O(1)-B-N torsion angle of 7.7(3)° and the B-O(1) bond distance of 1.420(3) Å suggest some double-bond character between oxygen and boron (sum of single-bond covalent radii = 1.48 Å).…”