The reactions of 18-crown-6 with each of K2[M(mnt)2](M=Zn, Hg; mnt=1,2-dicyanoethene-1,2-dithiolate, C2S2(CN)2-2) were studied and novel complexes [K(18-C-6)]2[Zn(mnt)2](1) and [K(18-C-6)]2[Hg(mnt)2](2) were characterized by elemental analysis, IR spectrum and X-ray diffraction analysis. Complex 1 displays a one-dimensional chain of [K(18-C-6)]2[Zn(mnt)2] bridged by K-O interactions between adjacent [K(18-C-6)]+ units. Complex 2 is also a one-dimensional chain of [K(18-C-6)]2[Hg(mnt)2] bridged by K...S weak interactions between adjacent [K(18-C-6)]+ and [Hg(mnt)2]2-.