Naslov
Polymorphs of phenazine hexacyanoferrate(II) hydrate: supramolecular isomerism in a 2D hydrogen‐bonded network

Autori
Cvrtila, Ivica ; Stilinović, Vladimir

Izvornik
Acta Crystallographica Section B-Structural Science Crystal Engineering and Materials (2052-5206) 77 (2021), 2; 211-218

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

Ključne riječi
crystal structure ; polymorhism ; hydrogen bond ; phenazine ; hexacyanoferrate

Sažetak
The crystal structures of two polymorphs of a phenazine hexacyanoferrate(II) salt/cocrystal, with the formula (Hphen)3[H2Fe(CN)6] [H3Fe(CN)6]·2(phen)·2H2O, are reported. The polymorphs are comprised of (Hphen)2[H2Fe(CN)6] trimers and (Hphen)[(phen)2(H2O)2][H3Fe(CN)6] hexamers connected into two‐dimensional (2D) hydrogen‐bonded networks through strong hydrogen bonds between the [H2Fe(CN)6]2− and [H3Fe(CN)6]− anions. The layers are further connected by hydrogen bonds, as well as through π–π stacking of phenazine moieties. Aside from the identical 2D hydrogen‐bonded networks, the two polymorphs share phenazine stacks comprising both protonated and neutral phenazine molecules. On the other hand, the polymorphs differ in the conformation, placement and orientation of the hydrogen‐ bonded trimers and hexamers within the hydrogen‐bonded networks, which leads to different packing of the hydrogen‐bonded layers, as well as to different hydrogen bonding between the layers. Thus, aside from an exceptional number of symmetry‐independent units (nine in total), these two polymorphs show how robust structural motifs, such as charge‐ assisted hydrogen bonding or π‐stacking, allow for different arrangements of the supramolecular units, resulting in polymorphism.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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