Crown ether alkali metal TCNQ complexes revisited - the impact of smaller cation complexes on their solid-state architecture and properties

The solid-state behaviour of four alkali metal TCNQ complexes: (15-crown-5) LiTCNQ (1), (15-crown5) NaTCNQ (2), (15-crown-5) Li.TCNQ)(2)center dot H2O (3 center dot H2O) and (15-crown-5) Na.TCNQ)(2)center dot H2O (4 center dot H2O) has been explored by single crystal X-ray diffraction, infrared (IR), Raman and electron paramagnetic resonance (EPR) measurements. The presence of a small cation and ionophore leads to subtle changes in behaviour compared with their larger alkali metal analogues and in the hydrated salts water bridges form links between the crown-encapsulated cations and neighbouring TCNQ stacks.