Synthesis and crystal structure of catena-poly[[bis(pyridine-4-carbonitrile-κN 1)cobalt(II)]-di-μ-thiocyanato-κ2 N:S;κ2 S:N].

The asymmetric unit of the title compound, [Co(NCS)2(C6H4N2)2] n (C6H4N2 = pyri-dine-4-car-bo-ni-trile), consists of two crystallographically independent cobalt cations that are located on centers of inversion as well as two independent thio-cyanate anions and two independent pyri-dine-4-car-bo-ni-trile coligands that occupy general positions. Each of the cobalt cations is sixfold coordinated by two N- and two S-bonding thio-cyanate anions and two pyri-dine-4-car-bo-ni-trile coligands in an slightly distorted CoN4S2 octa-hedral geometry with an all-trans coordination. The cobalt cations are linked by pairs of μ-1,3-bridging anionic ligands into linear chains. Powder X-ray diffraction (PXRD) experiments indicate that the title compound was obtained as a pure phase. Moreover, comparison of the experimental X-ray powder pattern of the residue obtained after water removal from [Co(NCS)2(C6H4N2)2(H2O)2] reported recently [Näther (2026 ▸).Acta Cryst. E82, 441-445] with the calculated powder pattern of the title compound proves that the latter crystalline phase has formed and indicates that a second modification with the same composition as that of the title compound might exist.