This research program is being supported by the Organic Synthesis Program. Aspects of the chemistry of compounds containing sulphur, selenium and tellurium will be pursued which have the potential to impact on a diverse number of areas such as organic metals and optical sensors. The investigation in organochalcogen chemistry will emphasize the following areas: l. Organosulfur Chemistry The chemistry of little explored types of thiocarbonyl compounds will be studied (e.g., thioquinones, thionoanhydrides). Other sulfur heterocycles which are potential pi donors (e.g., tetrathiafulvalene derivatives, polythiophenes, etc.) or LB film candidates will also be objects of investigation. 2. Organoselenium Chemistry Attention will be focussed on new organoselenium reagents, new selenium-containing pi donors, and selenocarbonyl derivatives. 3. Organotellurium Chemistry New tellurium-containing TTF and vinylogous TTF derivatives will be synthesized. Attempts will be made to synthesize tellurium analogs of the well known 1,2,3-thiadiazoles. The chemistry of new tellurium-containing functional groups will be investigated.