Monodentate Coordination of 4,4′‐Bipyridine Leading to a Supramolecular Network – Synthesis and Crystal Structure of [H 2 bpp][{Cu(Hbpy) 2 }{α‐HP 2 W 18 O 62 }]·4H 2 O

The new supramolecular compound [H 2 bpp][{Cu(Hbpy) 2 }{α‐HP 2 W 18 O 62 }]·4H 2 O ( 1 ) (bpy = 4,4′‐bipyridine, bpp = 1,3‐bis(4‐pyridyl)propane) was synthesized hydrothermally and characterized byelemental analysis, IR spectroscopy, thermogravimetric analysis and single‐crystal X‐ray diffraction. In compound 1 , the cationic fragment [Cu(Hbpy) 2 ] + connects to the Dawson anion through a coordinating Cu←O bond, and the copper atom is coordinated by another polyoxoanion through a weak covalent bond with a Cu1–O26 distance of 2.879(2) Å, forming a polymeric chain. The bpy ligand in [Cu(Hbpy) 2 ] + adopts a monodentate coordination mode, the other nitrogen atom of the bpy ligand is protonated. The protonated Hbpy + acts as hydrogen‐bond donor and constructs a two‐dimensional double‐sheet supramolecular network involving the one‐dimensional chains through the hydrogen bonds. The H 2 bpp 2+ ion connects twoα‐HP 2 W 18 O 62 6– clusters from two supramolecular networks through hydrogen bonds and creates a three‐dimensional supramolecular architecture. The thermal decomposition of 1 happens over a wide temperature range (450–800 °C), which indicates that it might include complicated oxidation–reduction processes.