Assemblies of luminescent ruthenium(II)— and osmium(II)—polypyridyl complexes based on hydrogen bonding

摘要: Abstract The spectroscopic properties of complexes denoted as Ru(tBu2bpy)2(bpy-X)2+ (RuX) and Os(tBu2bpy)2(bpy-Y)2+ (OsY) are reported (bpy is 2,2′-bipyridine tBu2bpy 4,4′-bis-(tert-butyl)-2,2′-bpy). X Y pairs functional groups containing bases known to be capable hydrogen bonding; X/Y  adenine/thymine (A/T) form double bonds, cytosine/guanine (C/G) can triple bonds. association processes for the Ru-X/OsY couples bearing complementary base in dichloromethane have been investigated by using 1H NMR or luminescence spectroscopy. couple responsible a low constant RuA · TOs associate, KA∼ 102 M−1, mixtures OsT do not give significant amounts associate solution at highest concentrations used studies (∼10−4M) By contrast, bonding interaction RuC/OsG results KA ⩾ 5 × 103 M−1 22 °C, evaluated before after addition ethanol. photoinduced Ru→Os energy transfer within RuC GOs (exothermicity ca. 0.3 eV) could monitored with use time-resolved spectroscopy was found occur rate ken = 9.3 107 s−1.