STEREOISOMERS OF MONORUTHENIUM(II), DIRUTHENIUM(II), AND TRIRUTHENIUM(II) COMPLEXES CONTAINING THE BRIDGING LIGAND 1,4,5,8,9,12-HEXAAZATRIPHENYLENE AND STUDIES OF THEIR PHOTOPHYSICAL PROPERTIES

A combination of synthetic methods involving mononuclear precursors of predetermined chirality (Delta- or Lambda-[Ru-(pp)(2)(CO)(2)](2+); pp = 2,2'-bipyridine or 1,10-phenanthroline) and chromatographic techniq ues has allowed the isolation of the meso (Delta Lambda) and rac (Delt a Delta/Lambda Lambda) diastereoisomers of the dinuclear complexes [(R u(pp)(2))(2)(mu-HAT)](4+) (HAT = 1,4,5,8,9,12-hexaazatriphenylene). Th e enantiomers of the rac forms have been separated, and characterizati on of all species has been achieved by NMR and CD studies. Additonally , the homochiral (Delta(3)/Delta(3)) and heterochiral (Delta(2) Lambda /Lambda(2) Delta) diastereoisomers of the trinuclear complexes [{Ru(pp )(2))(2)(mu-HAT)](6+), and the enantiomers of both forms, have been is olated and identified. Emission studies of all the dinuclear species a t room temperature indicate the relative luminescence quantum yields a nd the emission lifetimes significantly decrease for the meso compared with the rac diastereoisomers. No significant differences were detect ed at room temperature in the diastereoisomeric forms of the trinuclea r compounds. However, in a glass at low temperature (80 K), the lumine scence lifetimes of the trinuclear heterochiral diastereoisomer were s lightly shorter than those of the homochiral form.