The use of copper(I) halides as a preparative tool is discussed with respect to the synthesis of adduct compounds with new polymeric and oligomeric main group molecules. By using this approach new polymers of main group elements--some of which have been predicted by theoretical investigations--can be obtained in a crystalline state and are therefore accessible for a basic structural characterization. Thus, it becomes possible to compare the structural data, experimental data, and theoretical results. Mixed copper halide chalcogenides are accessible when complex copper thiometalates and copper halides are combined. These solid-state compounds are of special interest since they provide experimental access to new main group molecules. In addition, they exhibit a high copper ion conductivity when certain structural features are present in the compounds. A survey is given of basic synthetic and general structural aspects.