Synthesis, Upconversion Luminescence and Magnetic Properties of New Lanthanide–Organic Frameworks with (4 3 ) 2 (4 6 ,6 6 ,8 3 ) Topology

The synthesis and crystal structures of three new lanthanide–organic frameworks [Ln(pza)(OH)(H 2 O)] n (Ln = Y( 1 ), Er( 2 ), Yb( 3 ); H 2 pza = 2,3‐pyrazinedicarboxylic acid) with helical chains and novel 2D (4 3 ) 2 (4 6 ,6 6 ,8 3 ) topology are reported. The topology is obtained by simplifying the dinuclear metal core as a six‐connected node and the ligand as a three‐connected linker. The upconversion property measurement gives green and red emissions coming from two‐photon excitation of Y: Er, Yb codoped coordination polymer and arising from Er III transitions of 4 S 3/2 / 2 H 11/2 → 4 I 15/2 and 4 F 9/2 → 4 I 15/2 . The magnetic properties of complexes 2 and 3 are also studied.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)