Syntheses, structures and luminescent properties of three cadmium coordination polymers derived from (4-carboxymethoxy-phenyl)-acetate

Three new cadmium(II) coordination polymers {[Cd(bipy)(cpa)(H2O)]·2H2O}n (1), {[Cd(phen)(cpa)]·3H2O}n (2) and [Cd(cpa)]n (3) (bipy = 2,2′-bipyridine, phen = 1,10-phenanthroline, H2cpa = (4-carboxymethoxy-phenyl)-acetic acid) were synthesized and characterized. The cpa ligands exhibit the versatile coordination modes and play an important role in the construction of their structures. The structures of 1, 2 and 3 are comprised of one-dimensional chains, infinite molecular ladders and a (4,4)-connected (each Cd(II) links four cpa and each cpa connects four Cd(II)) three-dimensional network, respectively. 1, 2 and 3 reveal the blue emission maximum at 414, 420 and 458 nm, respectively, in the solid state at room temperature.