Tether Length Control of Topology in Cadmium 4-Methylphthalate Two-Dimensional Coordination Polymers: An Acentric Buckled Grid and a Rare Self-Catenated Layer

Hydrothermal synthesis has afforded a pair of dual-ligand divalent cadmium 4-methylphthalate (mph) two-dimensional (2-D) coordination polymers, wherein the length of the dipyridyl co-ligand plays a predominant role in the overall structural topology. [Cd-2(mph)(2)(dpe)(4)](n) (1, dpe = 1,2-di(4-pyridyl)ethane) possesses an acentric buckled (4,4) grid topology, with a pendant, monodentate dpe ligand bound to each Cd atom. Use of a slightly longer dipyridyl tether allowed generation of the 2-D phase [Cd-2(mph)(2)(dpp)(3)](n) (2, dpp = 1,3-di(4-pyridyl)propane). The dpp ligands in 2 all bridge two cadmium atoms, promoting the formation of a very rare 4-connected 6(6) self-catenated layer topology. Luminescent and thermal properties of 1 and 2 are also discussed.