The crystal structures of [(ferrocenylmethyl)trimethyl-ammonium](2)[Zn (dmit)(2)], {[FcCH(2) NMe3](2)[Zn(dmit)(2)]}, (4), and {[NEt4](2)[Zn(dmit)(2)]. MeOH} (5) are reported (dmit = 1,3-dithiole-2-thione-4,5-dithiolato). The dihedral angle between the C-5 planes in the [FcCH(2)NMe(3)](+) cation of 4 is 1.66 degrees; the C-5 rings are within 1.6(4)degrees of an eclipsed conformation. The zinc atoms in both the ionic complexes have distorted tetrahedral geometries. The bite angles of the dmit ligands are 93.67(4)degrees in 4 and 93.43(8) and 94.01(9)degrees in 5, with the remaining S--Zn--S bond angles having distinct values in the two complexes. The Zn-S bond lengths are similar in the two complexes being in the range 2.3311(12) to 2.350(2) Angstrom. Different interanionic S ... S contacts in the two complexes, at distances less than twice the van der Waals radius of S, lead to different packing arrangements. Spectral details (NMR, IR and VV-visible) of 4 and [FcCH(2)NMe(3)](2)[Zn(dmio)(2)] (6, dmio = 1,3-dithiole-2-one-4,5-dithiolato) have also been obtained. (C) 1997 Elsevier Science Ltd.