Synthesis, structure and characterization of two Cd(II) coordination polymers with helical structures

Two coordination polymers, [Cd2Cl2(1,3-BDC)(TTBT)(H2O)] (1) and [CdCl(1,4-HBDC)(TTBT)] (2) (1,3-BDC = 1,3-benzenedicarboxylate, 1,4-BDC = 1,4-benzenedicarboxylate, and TTBT = 10,11,12,13-tetrahydro-4,5,9,14-tetraaza-benzo[b]triphenylene), have been prepared under hydrothermal conditions and characterized by elemental analyses, IR spectra, thermal gravimetry (TG), fluorescence emission and single crystal X-ray diffraction analyses. The crystal structures were determined by X-ray diffraction and refined by full-matrix least-squares methods to R = 0.0621 and wR = 0.1543 using 4937 reflections with I 2(I) for 1; and R = 0.0525 and wR = 0.1427 using 3386 reflections with I 2(I) for 2. Compound 1 possesses a chiral chain structure. Adjacent chiral chains are further linked through - interactions between TTBT ligands to give a three-dimensional supramolecular architecture. Compound 2 displays a helical chain structure, with neighboring chains stacked by - interactions, generating an unusual three-dimensional supramolecular structure.