Structures and Properties of Two New Three‐Dimensional Inorganic‐Organic Hybrid Compounds Based on Isopolymolybdate Clusters

Two new inorganic‐organic hybrid materials containing different isopolymolybdate units, namely, [{Ce(pdca)(H 2 O)}{Ce(pdca)(H 2 O) 5 }] 2 {Mo 8 O 26 }·10H 2 O ( 1 ), [Cu(phen)(H 2 O) 2 ] 2 [Mo 6 O 20 ] ( 2 ) (pdca=pyridine‐2,6‐dicarboxylic acid, phen=1,10‐phenanthroline) have been successfully synthesized under hydrothermal conditions, and characterized by elemental analyses, IR spectra, thermal gravimetric analyses (TGA), single‐crystal X‐ray diffraction and powder X‐ray diffraction (PXRD). In compound 1 , Ce(III) ions are bridged by pdca ligands to form cerium‐organic coordination layers, which are further pillared by octamolybdate clusters via the covalent bonding of CeO, leading to the formation of a 3D pillar‐layered open‐framework architecture. Compound 2 features a 3D supramolecular structure constructed by hydrogen bond interactions between 1D molybdate chains aggregated by [Mo 6 O 20 ] 4− polyoxoanions and coordinated water molecules. It was remarkable that H 3 [PMo 12 O 40 ]· Χ H 2 O decomposes into hexamolybdate anions, which are linked together with phen ligands by Cu(II) cation. Moreover, UV‐vis spectra and fluorescence properties of compounds 1 – 2 have also been investigated in detail.