Boosting quantum yields and circularly polarized luminescence of penta- and hexahelicenes by doping with two BN-groups Appiarius, Yannik Míguez Lago, Sandra Miguel Álvarez, Delia González Campaña, Araceli A.G.C. and S.M.L. acknowledge grant PID2021-127521NB-I00 funded by MCIN/AEI/10.13039/501100011033, the European Regional Development Fund (ERDF) “A way of making Europe” and Ministerio de Economía y Competitividad (BES-2016-076371). S.M.L. acknowledges the Spanish Junta de Andalucía for funding. P.P. acknowledges the Central Research Development Fund of the University of Bremen for the postdoctoral fellowship. M.J. acknowledges the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement no. 716139) and the Swiss National Science Foundation (SNSF; no. PP00P2_198900). We thank Prof. A. J. Mota from the Department of Inorganic Chemistry from the University of Granada for performing additional DFT calculations. The incorporation of boron–nitrogen (BN) units into polycyclic aromatic hydrocarbons (PAHs) as an isoelectronic replacement of two carbon atoms can significantly improve their optical properties, while the geometries are mostly retained. We report the first non-π-extended penta- and hexahelicenes comprising two aromatic 1,2-azaborinine rings. Comparing them with their all-carbon analogs regarding structural, spectral and (chir)optical properties allowed us to quantify the impact of the heteroatoms. In particular, BN-hexahelicene BN[6] exhibited a crystal structure congruent with its analog CC[6], but displayed a fivefold higher fluorescence quantum yield (φfl = 0.17) and an outstanding luminescence dissymmetry factor (|glum| = 1.33 × 10−2). Such an unusual magnification of both properties at the same time makes BN-helicenes suitable candidates as circularly polarized luminescence emitters for applications in materials science. 2023-11-14T08:10:06Z 2023-11-14T08:10:06Z 2023-10-25 journal article Appiarius, Y. et al. Boosting quantum yields and circularly polarized luminescence of penta- and hexahelicenes by doping with two BN-groups. Chem. Sci., 2023. [DOI: 10.1039/d3sc02685j] https://hdl.handle.net/10481/85647 10.1039/d3sc02685j eng info:eu-repo/grantAgreement/EC/H2020/716139 http://creativecommons.org/licenses/by-nc/4.0/ open access Atribución-NoComercial 4.0 Internacional Royal Society of Chemistry