Isomer Directed Synthesis of Two 3D Cadmium(II) Compounds: Structure Variation and Energetic Performance

Bifunctional tetrazole-carboxylates, 5-(n-pyridyl)tetrazole-2-isopropionic acid (denoted as Hn-pytzipa, n = 2, 3) have been selected to be reacted with CdCl2·2.5 H2O under solvothermal conditions, [Cd3(2-pytzipa)2(MeOH)2Cl4]n (1) and [Cd(3-pytzipa)2]n (2) were obtained. In compound 1, 2-pytzipa is a pentadentate ligand to bridge adjacent Cd(II) centers to generate a fascinating 3D dinodal 4-connected, 5-connected net with point symbol of (42·84)(43·64·73). In 2, each 3-pytzipa bridges three Cd(II) atoms in a μ 1,3-COO syn-anti mode to generate a fascinating 3D one-nodal 6-connected net with point symbol of (42·52·66·75). Photoluminescence properties of compounds 1 and 2 in the solid state show enhanced ligand centered emission. Furthermore, thermogravimetric-differential (TG-DTG) and differential scanning calorimetry (DSC) were used to evaluate the thermal decomposition behavior of compounds 1 and 2, showing that the decomposition process of compound 2 is much more intense than that of compound 1. The thermal parameters (∆S, ∆H and ∆G) of the decomposition of compound 2 were calculated, as well.