Poly[bis-(μ 2 - N , N -di-methyl-formamide-κ 2 O : O )bis-(μ 4 -thio-phene-2,5-di-carboxyl-ato-κ 4 O : O ': O '': O ''')dicobalt(II)].

The asymmetric unit of the title three-dimensional metal-organic hybrid compound, [Co 2 (C 6 H 2 O 4 S) 2 (C 3 H 7 NO) 2 ] n , comprises two cobalt(II) cations, one residing on a twofold axis and the other on a centre of inversion, one thio-phene-2,5-di-carboxyl-ate (tdc 2- ) ligand and one coordinating di-methyl-formamide (DMF) solvent mol-ecule. Both of the cobalt(II) cations exhibit an octa-hedral coordination environment from the four carboxyl O atoms of the tdc 2- anions in a μ 4 - κ 1 : κ 1 : κ 1 : κ 1 fashion and two O atoms from DMF. A pair of carboxyl O atoms and one DMF molecule connect the adjacent cobalt(II) cations into an infinite chain, leading to a rod-spacer framework with rhombus-window channels, yet no residual solvent-accessible voids are present because the coordinating DMF molecules are oriented into the potential channels.