Four coordination networks constructed by MII/titb units (titb = 1,3,5-tris(imidazol-1-ylmethyl)-2,4,6-trimethylbenzene) pillared by “rods”

Four new coordination networks, namely, {[Cd3(titb)2(SO4)2(NO3)]·(NO3)·(H2O)}n (1), {[Co3(titb)2(L1)2.5Cl]·(H2O)4}n (2), {[Co3(titb)2(L2)3(H2O)]·(H2O)4}n (3) and {[Co2(titb)2(HL3)(H2O)3]Cl}n (4) (titb = 1,3,5-tris(imidazol-1-ylmethyl)-2,4,6-trimethylbenzene, H2L1 = octanedioic acid, H2L2 = 4,4′-(2,2′-oxybis(ethane-2,1-diyl)bis(oxy))dibenzoic acid and H4L3 = benzene-1,2,4,5-tetracarboxylic acid) have been successfully synthesized hydrothermally and structurally characterized by elemental analysis, IR spectra and X-ray diffraction analyses. All compounds contain MII/titb units, including 0D molecular cage for 1, 1D ladder-like chain for 3 and 2D sheets for 2 and 4, and all the counteranions (sulfate or carboxylate anions) act as a connector to pillar the MII/titb units to generate the 1D to 3D frameworks. Compound 1 exhibits a 1D chain based on discrete Cd3(titb)2 molecular cage connected by sulfates. Compound 2 is described in terms of 2D Co3(titb)2 sheet further linked by finite hexanuclear (Co6L15) chain to form a complicated 3D framework with pentanodal (3,4)-connected topology. Compound 3 is a 2D double-layer formed by the 1D Co3(titb)2 ladder-like chain connected by both pairs of (Co2L2Co3L2)n left-, right-handed helical chains and 1D (Co1L2)n linear chain. Compound 4 is tetranodal (3,5)-connected array based on Co2(titb)2 double-layered sheet pillared by HL4 ligands. Furthermore, the thermal and photoluminescent properties have also been studied.

This paper reports four new 1D to 3D coordination networks based on MII/titb units (a discrete molecular cage, a ladder-like chain and two 2D sheets) pillared by “rod”.Figure optionsDownload as PowerPoint slide