Coordination Polymers Constructed from TCNQ2– Anions and Chelating Ligands
Coordination polymers containing tetracyanoquinodimethane (TCNQ) in its dianionic form, TCNQ–II, have been formed by combining the acid form of the dianion, TCNQH2, with divalent metal centres in the presence of chelating ligands such as 2,2′-bipyridine (bipy) and 1,10-phenanthroline (phen). When MnII or CdII is employed, two-dimensional (2D) corrugated sheet structures with the formula MII(TCNQ–II)L (M = Mn, Cd; L = bipy, phen) are obtained. In contrast, when CoII is used as the metal centre a complex three-dimensional (3D) structure of composition [CoII(TCNQ–II)(phen)] is formed. Despite the significant differences between the 2D and 3D network structures, the metal coordination geometry and the binding mode of the TCNQ dianion are very similar in all cases.