No abstract

Excited-state absorption spectra of the complexes [(bpy)2Ru(dpp)Ru(bpy)2]4+ and [Ru(bpy)2(dpp)]2+ (bpy = 2,2'-bipyridine, dpp = 2,3-bis(2-pyridyl)pyrazine) in ethanol have been obtained. The excited-state spectra of both complexes exhibit bands in the near-UV region (350 nm for the binuclear complex and 370 nm for the mononuclear complex). In the visible region, a residual metal-to-ligand charge-transfer transition from the remaining Ru(II) center of the binuclear complex to the second lowest r* orbital of the dpp ligand occurs. No comparable band appears in the spectrum of the mononuclear complex. Weak bands also occur in the 610-630-nm region in both complexes. The excited states of the binuclear and mononuclear complex decay with lifetimes of 80 ± 10 and 210 ± 20 ns, respectively, and both complexes emit in room-temperature ethanol solution (0 = 0.0012 ± 0.0003 and 0.011 ± 0.001). Spectroelectrochemistry has been used to characterize the reduced forms of the complexes. The first reduction of each complex occurs at the dpp ligand, and the spectra of these singly reduced complexes resemble the excited-state spectra.There is, however, significantly more absorption in the 450-500-nm region for the reduced complexes, consistent with the presence of one or two Ru(Il) centers capable of engaging in MLCT transitions. The second reduction of the binuclear complex occurs at the dpp ligand, while the second reduction of the mononuclear complex occurs at one of the bpy ligands. introduction Since the first observation* of luminescence from Ru(bpy)32+ (bpy = 2,2'-bipyridine) and the subsequent discovery of its rich Contribution from

Standardization of the bladder capacities of children will improve the precision of urodynamic evaluation. In an attempt to develop a practical guide to predict the normal bladder capacity during childhood the bladder capacities of 132 children without a clinically abnormal pattern of voiding were measured. When the bladder capacities are correlated by age the following linear relationship exists: normal bladder capacity (ounces) equals age (years) plus 2. The bladder capacities of 68 children with primary enuresis, frequency or infrequent voiding were then measured. Children with clinically infrequent voiding demonstrated large bladder capacities and those with frequency or enuresis demonstrated small bladder capacities compared to normal children. The formula appears to be a useful guide to predict normal bladder capacity by age and also to aid in the diagnosis of abnormal voiding patterns.