The association of optically active ions. 2. The Pfeiffer-active system tris(1,10-phenanthroline)zinc(II) with adenosine 5′-monophosphate and related compounds

Article abstract of DOI:10.1021/ic50204a040

The system tris(1,10 phenanthroline)zinc(II) with adenosine 5′-monophosphate shows remarkable Pfeiffer activity. Noteworthy is the fact that the related compounds adenosine and α-ribose phosphate show little or no Pfeiffer activity in the pH range studied. The pH dependence indicates that a number of processes occur. At low pH the effect is most pronounced. It is concluded that short-range interaction between the purine base and the ligand rings is intimately involved in the ionic association process. The enhancement of the Pfeiffer effect in the protonated species may be due to a charge-transfer interaction from the ligands to the environmental compound. Protonation of the purine base would therefore make it a better electron acceptor. All Pfeiffer-active systems are shown by Job's method to involve 2 mol of environmental compound/mol of zinc complex.