Computational prediction of supramolecular assembly based on pentacopper(II) 12-MC-4 metallamacrocycles with 3-hydroxy-4-pyridinone moieties

DFT calculations predict an association of the copper(II)-containing β-alaninehydroxamic 12-metallacrown-4 (12-MC-4) and cuprate derivatives of the 3-hydroxy-4-pyridinones (3,4-HPs) in molecular ensembles. Noncovalent interactions forming the ensembles are analyzed with QTAIM and RDG approaches. Among the crucial contacts revealed are hydrogen bonds of the NH₂⋯OC(O) type and apical CuO interactions. Differences between the coordination environments of the central Cu²⁺ ion in 12-MC-4 and cuprates are displayed by ELF. Possible patterns of an ensemble arrangement in a crystal phase are suggested. On the basis of spatial structures formed by the NH₂⋯OC(O) and CuO interactions and computed dipole moments, the patterns are predicted to be of 1D and 2D packing. Energy changes on formation of corresponding molecular ensembles from separate 12-MC-4 and cuprate species in the polar medium of methanol are 0.7 and −19.2 kcal/mol by PBE0/DGDZVP. The PBE0 results are compared with TPSSH calculations employing the same basis set.