Crystal structure of catena-poly[[[tetra­aquacobalt(II)]-μ2-1,5-di­hydroxy­naphthalene-2,6-di­carboxyl­ato] di­methyl­formamide disolvate]

Abstract

The asymmetric unit of the title compound, {[Co(C₁₂H₆O₆)(H₂O)₄]·2C₃H₇NO}_n or {[Co(H₂dondc)(H₂O)₄]·2DMF}_n, comprises half of a Co^II ion, half of a 1,5-di­hydroxy­naphthalene-2,6-di­carboxyl­ate dianion (H₂dondc²⁻), two water mol­ecules and a di­methyl­formamide (DMF) mol­ecule. The key feature of the structure is a three-dimensional hydrogen-bonding network that consists of one-dimensional (1D) coordination chains built up by CoO₆ octa­hedra bridged by H₂dondc²⁻ ligands and inter­chain O–H⋯O hydrogen-bonding inter­actions.

The asymmetric unit of the title compound, {[Co(C₁₂H₆O₆)(H₂O)₄]·2C₃H₇NO}_n or {[Co(H₂dondc)(H₂O)₄]·2DMF}_n, comprises half of a Co^II ion, half of a 1,5-di­hydroxy­naphthalene-2,6-di­carboxyl­ate dianion (H₂dondc²⁻), two water mol­ecules and a di­methyl­formamide (DMF) mol­ecule. The Co^II ion, which is located on a crystallographic inversion center, exhibits a distorted six-coord­inated octa­hedral geometry with two oxygen atoms of the H₂dondc²⁻ ligand and four oxygen atoms of the water mol­ecules. The carboxyl­ate group is almost coplanar with the naphthalene moiety and shows monodentate coordination to the Co^II ion. The Co^II ions are bridged by the H₂dondc²⁻ ligand to form a one-dimensional chain. The hy­droxy groups of the ligand have intra-chain hydrogen bonding inter­actions with coordinated water mol­ecules. The coordinated water mol­ecules exhibit not only intra-chain hydrogen bonding inter­actions, but also inter-chain hydrogen-bonding inter­actions. The chains are connected by inter-chain hydrogen-bonding inter­actions and are arranged in parallel to form a two-dimensional network. The chains are further connected by inter-chain hydrogen-bonding inter­actions via the DMF mol­ecules and C—H⋯π inter­actions to give a three-dimensional network.