A new type of 3D [(MII)2(TCNQ-II)3]2- coordination network with spacious channels of hexagonal cross-section generated from TCNQH2

The dianion of tetracyanoquinodimethane, TCNQ(2-), is able to act as a ligand capable of binding four metal ions at the corners of a rectangle. When the ligand is combined with divalent metal ions in the presence of appropriate counterions, infinite anionic networks may be formed of composition [M(2)TCNQ(3)](2-) (M = Mn, Zn, Cd). In the structures reported here the cyano groups from six separate TCNQ dianions provide an octahedral coordination environment around the metal centres. Large hexagonal channels in the anionic network are occupied by highly disordered countercations.