COMPLEXATION CHEMISTRY OF CYCLOHEXAAMYLOSES .3. PER-O-METHYLCYCLOHEXAAMYLOSE ADDUCTS WITH 4-BIPHENYLCARBOXYLATE AND PARA-METHYLCINNAMATE ANIONS

Conductometric and 13C NMR spectrometric analyses of aqueous solutions containing 4-biphenylcarboxylate (BPC) or p-methylcinnamate (PMC) anions and per-O-methylcyclohexaamylose (MCy) indicate formation of MCy2, MCyηBPC, MCy2-BPC, MCy-PMC, and MCy 2ηPMC complexes. Values of equilibrium constants for each complex formation reaction were estimated at 30 °C. Intrinsic ,3C chemical shifts of the various adducts were calculated as well. These are discussed in terms of (1) preferential binding of phenyl and p-tolyl terminals of BPC and PMC, respectively, in the binary complexes, (2) face to face orientations of the wide MCy 2 apertures in the MCy 2 and ternary adducts, and (3) noncentered occlusion of the PMC anion within the cavity of its ternary complex. © 1979, American Chemical Society. All rights reserved.