Upon the addition of cations, the observed electrochemical behavior of crown ether compounds containing or bearing reducible functions sometimes exhibits two waves or sometimes a single wave that is shifted in position relative to the original redox couple. The type of electrochemical behavior observed depends upon the binding (stability) constant (Ks) for the neutral ligand-cation Interaction and the binding constant (KSE) for the reduced ligand-cation Interaction. A computer-based, digital simulation scheme has been devised that leads one to the conclusion that two distinct waves will be observed only when the initial cation binding constant is

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Silver (Ag+), sodium (Na+), and lithium (Li+) cation binding affinities (log Ks, acetonitrile, 25 °C) have been determined by using potentiometric methods for 18 lariat ethers and bibracchial lariat ethers (BiBLEs) including nine previously unreported compounds. The 2V-benzylaza-15-crown-5 derivatives 1-9 bear the following substituents on the aromatic ring: H, 2-nitro, 4-nitro, 2-cyano, 4-cyano, 2-chloro, 4-chloro, 2-methoxy, and 4-methoxy. Nine derivatives of IVJV-dibenzyl-4,13-diaza-18-crown-6 10-18 were also prepared having the same range of substituents.The ratio of binding constants, K/KH, for all three cations correlates well with the Taft inductive constants (cr°) with the best correlation observed for Ag+. p values for the binding reactions between monoaza and diaza crowns, respectively, with the indicated cations are Ag+, -1.08 and -1.28; Li+, -1.00 and -0.78; and Na+, -1.91 and -1.00.