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) 2 LiTCNQ ( 1 ), (12-crown-4) 2 NaTCNQ ( 2 ), (12-crown-4) 2 Li(TCNQ) 2 ( 3 ), (12-crown-4) 2 Na(TCNQ) 2 ( 4 ), and (12-crown-4) 2 K(TCNQ) 2 ( 5 ), reveals an unusual " cross-stitch " packing motif with the extended face-to-face π-stacked TCNQ&z.rad; − columns present in complexes 1 and 2 . The effect of the presence of additional neutral TCNQ 0 has also been explored. An unusual crossed dimer motif is present in the solid state in the infinite TCNQ&z.rad; − columns of the bis-12-crown-4 complexes of Li and NaTCNQ.