TY - JOUR A1 - Monroy, José del Refugio A1 - Deshpande, Tejas A1 - Schlecht, Joël A1 - Douglas, Clara A1 - Stirling, Robbie A1 - Grabicki, Niklas A1 - Smales, Glen Jacob A1 - Kochovski, Zdravko A1 - Fabozzi, Filippo Giovanni A1 - Hecht, Stefan A1 - Feldmann, Sascha A1 - Dumele, Oliver T1 - Homochiral versus racemic 2D covalent organic frameworks N2 - The synthesis of homochiral two-dimensional covalent organic frameworks (2D COFs) from chiral π-conjugated building blocks is challenging, as chiral units often lead to misaligned stacking interactions. In this work, we introduce helical chirality into 2D COFs using configurationally stable enantiopure and racemic [5]helicenes as linkers in the backbone of 2D [5]HeliCOFs as powders and films. Through condensation with 1,3,5-triformylbenzene (TFB) or 1,3,5-triformylphloroglucinol (TFP), our approach enables the efficient formation of a set of homochiral and racemic 2D [5]HeliCOFs. The resulting carbon-based crystalline and porous frameworks exhibit distinct structural features and different properties between homochiral and racemic counterparts. Propagation of helical chirality into the backbone of the crystalline frameworks leads to the observation of advanced chiroptical properties in the far-red visible spectrum, along with a less compact structure compared with the racemic frameworks. Homogeneous thin films of [5]HeliCOFs disclosed photoluminescent properties arising from the controlled growth of highly ordered π-conjugated lattices. The present study offers insight into general chiral framework formation and extends the Liebisch−Wallach rule to 2D COFs. KW - Chirality KW - Covalent organic frameworks KW - Diffraction KW - Lattices KW - Thin films PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-633755 DO - https://doi.org/10.1021/jacs.5c01004 SN - 0002-7863 VL - 147 IS - 21 SP - 17750 EP - 17763 PB - American Chemical Society (ACS) CY - Washington, DC AN - OPUS4-63375 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -