Luminescent and Magnetic Properties of Coordination Polymers Induced by Coordinating Modes of a Bis(oxamate) Ligand.

The reactions of an unexploited N,N′‐5‐carboxyl‐1,3‐phenylenebis(ethyl oxamate) (HEt2L) ligand with different Mn2+ and Cd2+ salts under solvothermal conditions afforded four three‐dimensional (3D) coordination polymers (CPs): [Mn1.5L(H2O)2]⋅H2O (1) [Mn2L(C2O4)0.5(NMP)(H2O)] ⋅ NMP (2), [Cd1.5L(H2O)2.5] ⋅ H2O (3) and [Cd2L(C2O4)0.5(H2O)3] ⋅ H2O (4) (NMP=N‐methyl pyrrolidone). L, generated by the in‐situ hydrolysis of HEt2L, displays four kinds of coordinating modes through oxamate and carboxylate groups as well as different syn‐syn and syn‐trans configurations. The resulting novel (3,4,5)‐, (3,4,6)‐, (4,5)‐ and (4,4,4,5)‐connected topologies for 1–4 were formed. Among them, 1 has interesting 1D metal‐oxamate zigzag chains, 2 contains 1D channels with a free void of 52.5 %, 3 consists of an unprecedented Cd‐oxamate layer, 4 has a novel Cd‐oxamate‐oxalate chain. The antiferromagnetic interactions of 1 and 2 were observed, meanwhile 3 and 4 exhibit solid‐state luminescence with the maximum emission bands at 483 and 479 nm, respectively, under an excitation of 332 nm. Structural Diversity: Four novel coordination polymers (CP) were constructed by Mn2+ and Cd2+ ions with N,N′‐5‐carboxyl‐1,3‐phenylenebis (oxamic acid), showing framework diversity caused by various ligand coordinating modes (See figure). In addition, antiferromagnetic interactions and exhibit solid‐state luminescence properties were investigated. [ABSTRACT FROM AUTHOR]