Diammine(2,2′-bipyridine)­bis(thio­cyan­ato­-κN)cobalt(III) diamminetetra­kis(thio­cyanato­-κN)chromate(III) aceto­nitrile disolvate

The new heterometallic title complex, [Co(NCS)(2)(C(10)H(8)N(2))(NH(3))(2)][Cr(NCS)(4)(NH(3))(2)]·2CH(3)CN, has been prepared using the open-air reaction of cobalt powder, Reineckes salt and 2,2′-bipyridine (dpy) in acetonitrile. The crystal structure consists of discrete cationic [Co(NCS)(2)(NH(3))(2)(dpy)](+) and anionic [Cr(NCS)(4)(NH(3))(2)](−) building blocks, both with 2 symmetry, and acetonitrile solvent mol­ecules, which are linked together by N—H⋯N hydrogen bonds, forming extended supra­molecular chains. Furthermore, N—H⋯S, C—H⋯S and C—H⋯N hydrogen bonds inter­link neighbouring chains into a three-dimensional framework. The Co atom is in an elongated octa­hedral coordination environment with two N atoms from the dpy ligands and two NCS-groups in the equatorial plane and with two NH(3) mol­ecules at the axial positions. The Cr(III) ion is octa­hedraly coordinated by two NH(3) mol­ecules at the axial positions and four NCS-groups in the equatorial plane. Intensity statistics indicated non-merohedral twinning with the twin matrix [100; 0[Image: see text]0; [Image: see text]0[Image: see text]]. The refined ratio of the twin components is 0.530 (1):0.470 (1).