A series of mono-functionalized core-modified expanded porphyrin building blocks such as thiasapphyrin, thiarubyrin, oxasmaragdyrin, and BF 2 -oxasmaragdyrin have been synthesized by simple condensation of readily available precursors. The mono-functionalized core-modified expanded porphyrin building blocks were used to synthesize the first three examples of covalently linked diphenylethyne-bridged dyads containing two different expanded porphyrin macrocycles, namely thaisapphyrin-BF 2 -oxasmaragdyrin, thiarubyrin-BF 2 -oxasmaragdyrin, and thiasapphyrin-thiarubyrin, by coupling appropriate mono-functionalized expanded porphyrin building blocks under mild Pd 0 coupling reaction conditions. The three dyads were freely soluble in common organic solvents and characterized by MS, NMR, absorption, electrochemical, and fluorescence techniques. The NMR, absorption, and electrochemical studies indicated that the two