Computational studies of ethynyl- and diethynyl-expanded tetrahedranes, prismanes, cubanes, and adamantanes

B3LYP/6-31+G(d) and MP2/6-31+G(d) computations are performed on a series of ethynyl- and diethynyl-expanded tetrahedranes, prismanes, cubanes and adamantanes. The poly-ynes express a broad range of absorption energies, indicating that these molecules are potential targets in expressly designed optical applications.