A New Class of Easily Generated TCNQ²⁻-Based Coordination Polymers

New types of coordination polymers containing [M(TCNQ)] sheets in which the TCNQ component is present as the little known dianion TCNQ2− are obtained in a very simple manner using readily available TCNQH2 (i.e. 1,4-(NC)2CH·C6H4·CH(CN)2) as the starting material. Above and below the metal centers in the sheets, a range of pyridine derivatives can be attached, some terminal and some acting as pillars linking sheet to sheet to form a 3D coordination network. The following compounds, generally in solvated form, were isolated and structurally characterized—[M(TCNQ)(pyridine)2] (M = Mn or Zn), [M(TCNQ)(quinoline)2] (M = Co or Zn), [Mn(TCNQ)(4-methylpyridine)2], [Zn(TCNQ)(4-phenylpyridine)2], [Zn(TCNQ)(isoquinoline)2], [Zn(TCNQ)(nicotinamide)2], [M(TCNQ)(bipy)] (M = Mn, Fe, Zn, Cd, and bipy =4,4′-bipyridine, which links sheet to sheet to generate 3D coordination polymers), [Zn(TCNQ)(bpe)] (bpe = 1,2-bis(4-pyridyl)ethylene), and [Zn(CH3OH)(TCNQ)(Obip)1/2] (Obip = 4,4′-bipyridine di-N-oxide). The TCNQH2/TCNQ2− app...