Divalent Metal Aliphatic Tricarboxylate Dipyridylamine Coordination Polymers with New or Rare Binodal Topologies

Abstract

Hydrothermal synthesis has afforded four divalent metal coordination polymers containing the aliphatic tricarboxylates tricarballylate (tca) or trans-aconitate (acon) and the kinked tethering co-ligand 4,4′-dipyridylamine (dpa). Diverse structural topologies are evident across this series, with coordination geometry and carboxylate binding mode serving important structure-directing roles. {[Cd2(tca)2(Hdpa)2]·7H2O}n (1) possesses one-dimensional (1-D) ribbon motifs with pendant Hdpa+ ligands and a new 4-connected supramolecular topology, along with co-crystallized water molecule tapes. {[Cd3(acon)2(dpa)2(H2O)2]·4H2O}n (2) has a 4,4-connected binodal lattice with frl (4264)4(6482) topology, while the structurally related phase {[Zn3(tca)2(dpa)2]·2H2O}n (3) has a 4,4-connected binodal lattice with a novel (426282)4(6284) topology. [Cu(Htca)(dpa)]n (4) manifests a 3,5-connected binodal net with rare (4.62)(4.6683) topology. Thermal stability of these materials is discussed. Complexes 1–3 undergo blue-violet light emission on excitation with ultraviolet light.