Alkali-Metal-Templated Assemblies of New 3D Lead(II) Tetrachloroterephthalate Coordination Frameworks

A series of novel metal organic frameworks (MOFs) have been assembled from Pb-II and 2,3,5,6-tetrachloro-1,4-benzenedicarboxylic acid (H2BDC-Cl-4) by simply adding different alkali metal ions as templates. When only lead nitrate is used, a robust 3D open framework [Pb(BDC-Cl-4) (MeOH)(2)](n) (1) with pts topolop can be obtained. Incorporating the lighter Li-I or Na-I ions into the above Pb-II/BDC-Cl-4 system results in two unique isostructural 3D and pb(II) - Na-I heterometallic frameworks, {[PbLi2(BDC-Cl-4)(mu(2)-OHM (H2O)}(n) (2) and [pbNa(2)(BDC-Cl-4)(mu(2)-OH)(2)](n) (3), which are built from the combination of a 3D rod-packing PBII-carboxylate framework and a 3D Na-I-BDC-Cl-4 (or Li-I-BDC-Cl-4) network. When the heavier K-I ion is applied, the similar reaction affords a 3D MOF [Pb-2(BDC-Cl-4)(2)(DMF)(3)](n) (4), which represents the first pillar-layered Phil coordination network with a (3,5)-connected gra topology. The results illustrate the powerful effect of the alkali-metal templates in MOFs assemblies. The solid-state properties such as thermal stability and luminescence of 1-4 have also been studied.