Syntheses, Structures, Photochemical and Magnetic Properties of Novel Divalent Cd/Mn Coordination Polymers Based on a Semirigid Tripodal Carboxylate Ligand

The reactions of a semirigid tripodal carboxylic ligand, 3,5-bi­(4-carboxy-phenoxy)-benzoic acid (H3BCPBA) with Cd­(NO3)2/Mn­(NO3)2 afford five novel complexes, {[Cd3(BCPBA)2·(DMA)2­·(H2O)5]·7H2O·2DMA}n (1), {[Cd3(BCPBA)2(L1)­(H2O)6]·(L1)}n (L1 = 4-[(E)-4-pyridinylazo]­pyridine) (2), {[Cd3(BCPBA)2(L2)­·(H2O)3(DMF)2]·2DMF}n (L2 = 1,3-bis­(4-pyridyl)­propane) (3), {[Mn3(BCPBA)2(H2O)4]·11H2O}n (4), {[Mn3(BCPBA)2(DMF)2(H2O)2]­·2DMF·9H2O}n (5) in the presence or absence of an auxiliary ligand. Compound 1 is a three-dimensional (3D) structure with 3,4-connected net structure. Compound 2 possesses 3D networks with two 3D → 3D interpenetration frameworks. Compound 3 is a 3D sheet structure with a decorated tfz-d topology. Compound 4 is a 3D structure which consists of a two-dimensional (2D) Mn honeycomb net with six infinite Mn rings and BCPBA3– ligands. Compound 5 is also a 3D structure, while its 2D Mn honeycomb net with eight infinite Mn rings is different from that of compound 4. The photochemical property of 1–3 is performed in the solid state at room temperature. Magnetic susceptibility measurements indicate that compounds 4 and 5 exhibit antiferromagnetic coupling between adjacent Mn­(II) ions.