Chalcogen Atom Size Dictates Stability of Benzene‐1,3,5‐triamide Polymers: Overlooked Role of Geometrical Fit for Enhanced Hydrogen Bonding.

Our quantum chemical analyses elucidated how the replacement of O in the amide bonds of benzene‐1,3‐5‐tricarboxamides (OBTAs) with the larger chalcogens S and Se enhances the intermolecular interactions and thereby the stability of the obtained hydrogen‐bonded supramolecular polymers due to two unexpected reasons: i) the SBTA and SeBTA monomers have a better geometry for self‐assembly and ii) induce stronger covalent (hydrogen‐bond) interactions besides enhanced dispersion interactions. In addition, it is shown that the cooperativity in benzene‐1,3,5‐triamide (BTA) self‐assembly is caused by charge separation in the σ‐electronic system following the covalency in the hydrogen bonds. [ABSTRACT FROM AUTHOR]