A photoacid-generating compound has the structure;;wherein m, n, R1, R2, X, Y, and Z− are defined herein. The photoacid-generating compound exhibits strong absorption and chemical sensitivity to extreme ultraviolet radiation, while also absorbing longer wavelengths with desirably reduced chemical sensitivity. Also described are a polymer incorporating the residue of a polymerizable version of the photoacid-generating compound, a photoresist composition that includes the photoacid-generating compound, the polymer, or a combination thereof, and a method of forming a photoresist relief image using the photoresist composition.