A novel pseudo-centrosymmetric P=O center dot center dot center dot H-O-H center dot center dot center dot O=P synthon in crystal structures of azaheterocyclic phosphonates

作者：Pietrzak Anna^*; Modranka Jakub; Wojciechowski Jakub; Janecki Tomasz; Wolf Wojciech M^*

来源：Journal of Molecular Structure, 2018, 1168: 135-144.

DOI：10.1016/j.molstruc.2018.05.026

• Heterocyclic phosphonates
• Energy frameworks
• Single crystal X-Ray analysis
• Supramolecular synthon
• Special position disorder

Crystals of novel azaheterocyclic phosphonates were characterized by the X-ray diffraction analysis supplemented by detailed calculations on interactions stabilizing the molecular assemblies. Intermolecular energies were evaluated using CrystalExplorer CE-B3LYP method. Additionally, fingerprint plots derived from Hirshfeld surfaces were generated for each structure to characterize the crystal packing arrangement in detail. Supramolecular systems formed by investigated compounds may be conveniently described as molecular saw tooth ribbons linked by the pseudo-centrosymmetric P=O center dot center dot center dot H-O-H center dot center dot center dot O=P synthon which for the first time was introduced in this paper. Water molecules are disordered around inversion center over four positions and encapsulated by ethoxy and phosphoryl groups. The resulting pockets are connected by narrow linkers and form tunnels with periodically changing diameter. Therefore, the most likely water molecules enter the crystal during crystallization. Their further transport is limited by the tight channel aperture. Topology of intermolecular interactions as represented by energy frameworks showed similarity of interaction nets in all systems. The TG/DTG and DSC analyses indicate that thermal stability of investigated crystals is closely related to their packing behavior which is not disturbed by associated water molecules.

• 出版日期2018-9-15