Naslov
A polar/π model of interactions explains face-to-face stacked quinoid rings: a case study of the crystal of potassium hydrogen chloranilate dihydrate

Autori
Molčanov, Krešimir ; Stare, Jernej ; Kojić-Prodić, Biserka ; Lecomte, Claude ; Dahaoui, Slimane ; Jelsch, Christian ; Wenger, Emmanuel ; Šantić, Ana ; Zarychta, Bartosz

Izvornik
Crystengcomm (1466-8033) 17 (2015); 8645-8656

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
pi-interactions ; chloranilic acid ; X-ray charge density ; periodic DFT ; intermolecular interaction

Sažetak
The nature of interactions between face-to-face staggered stacked quinoid rings with π-systems, observed with short inter-ring centroid∙∙∙centroid distance is analyzed by experimental and theoretical methods. Charge density studies based on X-ray diffraction and DFT calculations, complemented by impedance spectroscopy were employed to define the electronic and structural characteristics of the quinoid rings responsible for their interactions within the crystal packing. The crystal packing is mainly stabilized by strong electrostatic interactions between K+ cation and the hydrogen chloranilate anion. The proximity and orientation of the stacked quinoid rings in parallel glide-plane arrangement is partly governed by the non-covalent interactions within the dimer. The estimated contribution of dispersion energy to the stacking of the rings about -10 kcal mol-1, as calculated by DFT methods, is comparable to medium-strong hydrogen bonding. The electronic structure of 2, 5-dihydroxyquinonate monoanion exhibits alternating electron-rich and electron-poor regions. The calculated electrostatic energy shows variations with the relative orientation of rings within dimers reaching ca. 10-15 kcal mol-1. Thus, the nature of interactions between π-systems of quinoid rings can be described by a polar/π model where electrostatic complementarity plays a determinant role in π-stacking orientation. These interactions have a great potential in crystal engineering and may be employed in design of functional materials.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

Napomena
Djelomično financirala Zaklada HAZU (za 2014. godinu) i hrvatsko-francuska bilaterala - Cogito.

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