LUMINESCENT RUTHENIUM (II) COMPLEXES AND THEIR USE IN PH SENSORS

摘要

The invention provides luminescent Ru(ll) complexes that can be used in pH sensors to provide pH sensitivity over a wide pH range. The complexes have at least one polypyridyl ligand having at least one proton-accepting group with a pK_a in the range 4 to less than 6, wherein the luminescence intensity and/or luminescence lifetime of the complex varies depending on the protonation state of the proton-accepting group; and at least one polypyridyl ligand having at least one proton-donating group with a pK_a in the range 6 to 8, wherein the at least one proton-donating group is covalently linked to a ring carbon atom of the at least one polypyridyl ligand by a spacer group having the formula -(CH₂)_q- wherein q may be 1, 2, or 3, and wherein the luminescence intensity and/or luminescence lifetime of the complex varies depending on the protonation state of the proton-donating group.