Electronic energy transfer between ruthenium(II) and osmium(II) polypyridyl luminophores in a hydrogen-bonded supramolecular assembly

Complexes Ru-C and Os-G are derivatives of [Ru(bipy)(3)](2+) and [Os(bipy)(3)](2+) bearing peripheral cytosine (C) or guanine (G) nucleobases respectively; in CH2Cl2 these undergo association (K-A > 5000 dm(-3) mol(-1)) by hydrogen bonding between the complementary C/G groups, and Ru --> Os photoinduced energy-transfer occurs within Ru-C...G-Os associated pair.