Base-Directed Formation of Isostructural Lanthanide-Sulfate-Glutarate Coordination Polymers with Photoluminescence.

A series of five isostructural 3D lanthanide-based coordination polymers [Ln III 2 (H 2 O) 6 (glu)(SO 4 ) 2 ] n [Ln = Pr( 1 ), Nd( 2 ), Sm( 3 ), Eu( 4 ), and Gd( 5 )] was effortlessly obtained within a few minutes via the microwave-heating method. The employment of auxiliary bases, that is, sodium hydroxide, 4,4'-bipyridine, and 1,4-diazabicyclo[2.2.2]octane, led to the formation of the title complex, whereas base-free synthesis yielded a three-dimensional inorganic coordination polymer, [Ln 2 (H 2 O) 4 (SO 4 ) 3 ] n · n H 2 O, Ln = Nd ( 2a ). The robustness of the synthetic method was illustrated as both microwave-heating and conventional hydrothermal techniques also enabled the formation of a high-crystalline phase-pure complex 1 - 5 . In the structure of 1 - 5 , glutarato (glu 2- ) and sulfato ligands link dinuclear Ln(III) building units into three-dimensional frames. The glu 2- ligands act as tethering linkers, expanding the structure into a neutral 3D coordination network. Hydrogen bonds were found to be the predominant intermolecular interactions in the crystal structures. Photoluminescence of the complex 1 - 5 was studied.