TY - JOUR

T1 - From a 1,2-azaborinine to large BN-PAHs via electrophilic cyclization

T2 - Synthesis, characterization and promising optical properties

AU - Appiarius, Yannik

AU - Stauch, Tim

AU - Lork, Enno

AU - Rusch, Pascal

AU - Bigall, Nadja C.

AU - Staubitz, Anne

N1 - Funding Information: A.S. and Y.A. thank the German Research Foundation (DFG) for the Emmy-Noether-Grant STA1195/2-1. N.B. and P.R. thank the DFG for partial funding under Germany’s Excellence Strategy within the Cluster of Excellence PhoenixD (EXC 2122, Project ID 390833453) and the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No. 714429). We thank Philipp J. Gliese for his support in the optimization of the azaborinine precursor syntheses and Daniel Duvinage for his support in the cyclic voltammetry measurements.

PY - 2021/1/7

Y1 - 2021/1/7

N2 - We present a convergent synthetic route towards boron-nitrogen containing polycyclic aromatic hydrocarbons (BN-PAHs) that allowed us to synthesize six derivatives. Starting from the conjunction of a 1,2-azaborinine nucleophile and various aryl electrophiles, the key step was the extension of the aromatic system via an electrophilic ring closure of the respective alkyne precursors. Our route allows the use of substituted PAH precursors to be circumvented, which are often unavailable. Instead, it builds up the BN-PAHs solely from easily accessible monocycles. All derivatives were emissive in solution and solid state with quantum yields up to Φlum = 0.40 and small Stokes shifts. The emission wavelengths in solid state were notably dependent on the connectivity of the rings. Due to excimer formation in one derivative, its emission was significantly redshifted with a comparatively slow secondary photoluminescence (PL) decay.

AB - We present a convergent synthetic route towards boron-nitrogen containing polycyclic aromatic hydrocarbons (BN-PAHs) that allowed us to synthesize six derivatives. Starting from the conjunction of a 1,2-azaborinine nucleophile and various aryl electrophiles, the key step was the extension of the aromatic system via an electrophilic ring closure of the respective alkyne precursors. Our route allows the use of substituted PAH precursors to be circumvented, which are often unavailable. Instead, it builds up the BN-PAHs solely from easily accessible monocycles. All derivatives were emissive in solution and solid state with quantum yields up to Φlum = 0.40 and small Stokes shifts. The emission wavelengths in solid state were notably dependent on the connectivity of the rings. Due to excimer formation in one derivative, its emission was significantly redshifted with a comparatively slow secondary photoluminescence (PL) decay.

UR - http://www.scopus.com/inward/record.url?scp=85099030104&partnerID=8YFLogxK

U2 - 10.1039/d0qo00723d

DO - 10.1039/d0qo00723d

M3 - Article

AN - SCOPUS:85099030104

VL - 8

SP - 10

EP - 17

JO - Organic Chemistry Frontiers

JF - Organic Chemistry Frontiers

SN - 2052-4110

IS - 1

ER -