Structural and energetic aspects of adamantane and memantine derivatives of sulfonamide molecular crystals: experimental and theoretical characterisation

Abstract

A number of new sulfonamide compounds with adamantane and memantine fragments were synthesised and characterised. Their single crystals were grown and crystal structures were determined. XPac analysis has revealed three sets of isostructural crystals based on adamantane/memantine-specific hydrogen bond patterns. The use of QTAIMC and Hirshfeld surface analysis allowed elucidating the influence of functional groups and molecular arrangement on the strength of inter- and intramolecular non-covalent interactions in crystals and overall packing efficiency. It was found that the bulky memantine fragment hinders the formation of C(4) hydrogen-bonded chains, leading to the formation of dimeric structures with lower stabilisation energy. The layered packing of hydrophobic fragments in the group of isostructural crystals was found to be the most effective for a group of adamantane derivatives of P2₁/c symmetry.