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Crystals of penta(carboxymethyl)diethylenetriamine have been structurally characterized through single‐crystal X‐ray diffraction analysis. X‐ray diffraction analysis reveals that various non‐covalent interactions combine to determine the crystal packing and final solid‐state supramolecular assembling behavior. The title compound exhibited various 2D supramolecular networks generated through O−H⋅⋅⋅O and C−H⋅⋅⋅O interactions. The C−H⋅⋅⋅O interactions are pivotal in building a two‐dimensional framework, whose formation is readily analyzed with zero‐dimensional centrosymmetric dimeric rings as building blocks within the structure. All the intermolecular interactions are quantified through Hirshfeld surface analysis and fingerprint plots. Energy frameworks are constructed to analyze the dominant interaction energy involved in molecular packing strength. Bader's quantum theory of "atoms‐in‐molecules" (QTAIM) has been used to analyze and characterize non‐covalent interactions. The QTAIM analysis validates the existence of hydrogen bonding contacts, and the topological properties of bond critical points (BCPs), such as the electron density ρ(r) and its Laplacian ∇2ρ(r), are presented to correlate with the interaction energy. The topological analysis revealed that all of the interactions are closed‐shell interactions. Finally, the "Non‐covalent Interaction" (NCI) plot index illustrates the solid‐state supramolecular networks. [ABSTRACT FROM AUTHOR]

A series of pyridinium-carboxylate salts (1–3) were designed, synthesized and structurally characterized to explore the importance of salt-bridge (SB) interactions in building self-assembled structures. We present a comprehensive analysis of the SB interaction in crystal structures of 4,4′-oxybis(benzoic acid) with substituted aminopyridines where the SBs display extremely well defined geometric preferences. In the solid-state, compound (1) exhibits lone-pair (l.p)⋯(SB)/(SB)⋯π+ assemblies while compound (2) shows a C–H⋯(SB)/(SB)⋯π network. Interestingly, compound (3) exhibits two distinct networks π+⋯(SB)/(SB)⋯(SB)/(SB)⋯π+ and C–H⋯(SB)/(SB)⋯H–C. These extended supramolecular networks are studied and described in detail. The duality of the SBs in stabilizing the π-facial interactions with electron rich and/or electron poor moieties is also described. The energetic and geometric features of salt-bridge interaction are studied and its impact on the resultant supramolecular organization is analyzed using theoretical DFT-D3 calculations. The theoretical study combines the energetic features of the noncovalent forces that participate in the extended network and the characterization of the diverse interactions by means of Bader's theory of 'atoms in molecules'(AIM). [ABSTRACT FROM AUTHOR]