A Series of New Three-Dimensional d–f Heterometallic Coordination Polymers with Rare 10-Connected<b>bct</b>Net Topology Based on Planar Hexanuclear Heterometallic Second Building Units

Abstract

A series of new three-dimensional (3D) d–f heterometallic coordination polymers, namely, [LnM(μ 5 -PyIDC)(μ 2 -INIC)(μ 3 -INIC)]· x H 2 O [Ln = Sm, M = Co, x = 3 ( 1 ); Ln = Sm, M = Ni, x = 1 ( 2 ); Ln = Eu, M = Co, x = 3 ( 3 ); Ln = Eu, M = Cd, x = 3 ( 4 ); Ln = Eu, M = Zn, x = 3 ( 5 ); Ln = Gd, M = Co, x = 3 ( 6 ); Ln = Gd, M = Cd, x = 3 ( 7 ); Ln = Tb, M = Co, x = 3 ( 8 ); Ln = Tb, M = Cd, x = 2 ( 9 ); Ln = Tb, M = Zn, x = 3 ( 10 ); H 3 PyIDC = 2-(pyridine-3-yl)-1H-4,5-imidazoledicarboxylic acid; HINIC = isonicotinic acid], have been successfully synthesized under hydrothermal conditions and structurally characterized. All the complexes are isostructural and exhibit novel 3D pillar-layered coordination frameworks constructed by the linkages of 2D heterometallic layers and INIC – pillars. Topological analysis indicates that those complexes possess a rare uninodal 10-connected bct topology based on planar hexanuclear heterometallic [Ln 2 M 4 (PyIDC) 2 ] second building units. To the best of our knowledge, complexes 1 – 10 represent examples of 3D lanthanide–transition heterometal–organic coordination polymers with highly connected bct networks. Moreover, the luminescence properties of complexes 3 – 5 and 7 – 10 and the magnetic properties of 6 – 8 were also investigated.