Photochemistry of gold nanoparticles functionalized with an iron(II) terpyridine complex. An integrated visible light photocatalyst for hydrogen generation.

Gold nanoparticles functionalized with iron(II) terpyridine complexes undergo upon laser flash excitation long-lived charge separation in both conventional organic solvents and ionic liquids. The nature of the transient species depends on the laser excitation wavelength, 308 (Fe(tpyR)(2)(3+) and Au-) or 532 nm (solvated e-). No transients in the microsecond timescale are observed in acetonitrile upon excitation of gold nanoparticles lacking iron(ii) terpyridine complexes. The photogeneration of long-lived transients upon irradiation of these functional gold nanoparticles has been applied to develop an integrated (light harvester plus catalyst) visible-light photocatalysts for H2 generation from water that does not need methyl viologen as an electron relay.