Synthesis, structural characterization and computational studies of catena-poly[chlorido[mu(3)-(pyridin-1-ium-3-yl)phosphonato-kappa O-3:O ':O '']zinc(II)]

Coordination polymers are constructed from two basic components, namely metal ions, or metal-ion clusters, and bridging organic ligands. Their structures may also contain other auxiliary components, such as blocking ligands, counter-ions and nonbonding guest or template mol\-ecules. The choice or design of a suitable linker is essential. The new title zinc(II) coordination polymer, [Zn(C$\sb 5$H$\sb 5$NO$\sb 3$P)Cl]$\sb \it n$, has been hydro\-thermally synthesized and structurally characterized by single-crystal X-ray diffraction and vibrational spectroscopy (FT--IR and FT--Raman). Additionally, computational methods have been applied to derive quanti\-tative information about inter\-actions present in the solid state. The compound crystallizes in the monoclinic space group \it C2/\it c. The four-coordinated Zn$\sp II$ cation is in a distorted tetra\-hedral environment, formed by three phospho\-nate O atoms from three different (pyridin-1-ium-3-yl)phos\-pho\-nate ligands and one chloride anion. The Zn$\sp II$ ions are extended by phospho\-nate ligands to generate a ladder chain along the [001] direction. Adjacent ladders are held together \it via N---H$ćdots$O hydrogen bonds and offset face-to-face $π$--$π$ stacking inter\-actions, forming a three-dimensional supra\-molecular network with channels. As calculated, the inter\-action energy between the neighbouring ladders is $-$115.2kJmol$\sp $-$1$. In turn, the cohesive energy evaluated per asymmetric unit-equivalent fragment of a polymeric chain in the crystal structure is $-$205.4kJmol$\sp $-$1$. This latter value reflects the numerous hydrogen bonds stabilizing the three-dimensional packing of the coordination chains.