Supramolecular Frameworks Based on Rhenium Clusters Using the Synthons Approach

Nathalie Audebrand; Antoine Demont; Racha El Osta; Yuri V Mironov; Nikolay G Naumov; Stéphane Cordier

doi:10.3390/molecules26092662

Supramolecular Frameworks Based on Rhenium Clusters Using the Synthons Approach

Molecules. 2021 May 1;26(9):2662. doi: 10.3390/molecules26092662.

Authors

Nathalie Audebrand¹, Antoine Demont¹, Racha El Osta¹, Yuri V Mironov², Nikolay G Naumov², Stéphane Cordier¹

Affiliations

¹ ISCR (Institut des Sciences Chimiques de Rennes)-UMR 6226, CNRS, Univ Rennes, F-35000 Rennes, France.
² Nikolaev Institute of Inorganic Chemistry, 3 Acad. Lavrentiev pr., 630090 Novosibirsk, Russia.

Abstract

The reaction of the K₄[{Re₆Sⁱ₈}(OH)^a₆]·8H₂O rhenium cluster salt with pyrazine (Pz) in aqueous solutions of alkaline or alkaline earth salts at 4 °C or at room temperature leads to apical ligand exchange and to the formation of five new compounds: [trans-{Re₆Sⁱ₈}(Pz)^a₂(OH)^a₂(H₂O)^a₂] (1), [cis-{Re₆Sⁱ₈}(Pz)^a₂(OH)^a₂(H₂O)^a₂] (2), (NO₃)[cis-{Re₆Sⁱ₈}(Pz)^a₂(OH)^a(H₂O)^a₃](Pz)·3H₂O (3), [Mg(H₂O)₆]_0.5[cis-{Re₆Sⁱ₈}(Pz)^a₂(OH)^a₃(H₂O)^a]·8.5H₂O (4), and K[cis-{Re₆Sⁱ₈}(Pz)^a₂(OH)^a₃(H₂O)^a]·8H₂O (5). Their crystal structures are built up from trans- or cis-[{Re₆Sⁱ₈}(Pz)^a₂(OH)^a_4-x(H₂O)^a_x]^x-2 cluster units. The cohesions of the 3D supramolecular frameworks are based on stacking and H bonding, as well as on H₃O_2-bridges in the cases of (1), (2), (4), and (5) compounds, while (3) is built from stacking and H bonding only. This evidences that the nature of the synthons governing the cluster unit assembly is dependent on the hydration rate of the unit.

Keywords: crystal engineering; rhenium sulfide cluster; supramolecular framework; synthon; topology.