Hydrogen bonded homodimetallic compounds of the formula [M(H₂O)₅M(dipic)2]·₂H2O, M = Co^II or Ni^II and dipic = dipicolinate anion

Two homodimetallic dipicolinate compounds of the formulae [Co(H₂O)₅Co(dipic)2]·2H₂O (1) and [Ni(H₂O)₅Ni(dipic)2]·2H₂O (2) have been synthesized and their crystal structures have been determined by single-crystal X-ray diffraction analysis. The prepared isostructural compounds consist of cationic {MO₅O’}²⁺ and anionic {MN₂O₄}^2- moieties, where Co^II/Co^II or Ni^II/Ni^II metal centers are connected together by bridging μ-carboxylate oxygen atoms from dipicolinate anions. H-bond interactions involving aqua ligands, dipicolinate oxygens and lattice solvent molecules stabilize the dimeric units by linking them into 3-D polymeric networks.