2D-coordination polymers constituted from indium halides and dipyridyl N-donor ligands

Four indium-based, 2D coordination polymers (CP) were synthesized utilizing InCl${}_3$ and InI${}_3$ and the bidentate ligands 4,4'-bipyridine (bipy), 1,2-di(4-pyridyl)ethylene (bpe) and 1,2-di(4-pyridyl)ethane (bpa). The isoreticular networks ${}_{\infty }^2$[In${}_2$Cl${}_6$(bipy)] (1) and ${}_{\infty }^2$[In${}_2$Cl${}_6$(bpe)] (2) are constituted by chloride- and ligand-bridged octahedra with a honeycomb like (6,3)-net topology (hcb topology). In contrast, ${}_{\infty }^2$[(In${}_4$Cl${}_{12}$)(bpa)${}_3$] (3) consists of {In${}_4$Cl${}_{12}$N${}_6$} units, with each indium atom being coordinated by chloride anions and bpa ligands in an octahedral fashion. Bpa ligands connect indium atoms in two dimensions, forming a semi-regular uninodal 3-c net with the point symbol (4,8${}^2$), as present in the fes topology. In ${}_{\infty }^2$[(InI${}_3$)${}_2$(bpa)${}_3$] (4), indium is coordinated by three iodide and three bpa ligands in a meridional fashion. In contrast to ${}_{\infty }^2$[In${}_2$Cl${}_6$(bipy)] (1) and ${}_{\infty }^2$[In${}_2$Cl${}_6$(bpe)] (2), the indium-centered octahedra are linked by the bidentate linker only, but also a honeycomb-like, zigzag-shaped (6,3)-net with a hcb topology is formed. The CPs were investigated by SCXRD, PXRD, IR-spectroscopy, and with DTA/TG regarding their thermal properties. (© 2021 The Authors. Zeitschrift für anorganische und allgemeine Chemie published by Wiley-VCH GmbH)