Novel TCNQ-stacking motifs in (12-crown-4)-complexes of alkali metal TCNQ salts

An investigation of the solid-state behaviour of five 12-crown-4 alkali metal TCNQ complexes, (12-crown-4)2LiTCNQ (1), (12-crown-4)2NaTCNQ (2), (12-crown-4)2Li(TCNQ)2 (3), (12-crown-4)2Na(TCNQ)2 (4), and (12-crown-4)2K(TCNQ)2 (5), reveals an unusual “cross-stitch” packing motif with the extended face-to-face π-stacked TCNQ˙− columns present in complexes 1 and 2. The effect of the presence of additional neutral TCNQ0 has also been explored.