Molecular Encapsulation of Redox‐Active Guests

Competition between Hydrogen Bonding and Proton Transfer during Specific Anion Recognition by Dihomooxacalix[4]arene Bidentate Ureas

“…This result suggests that the electrogenerated dianions (formed at peak IIc), bind in a fast and reversible reaction with the added urea . Due to the presence of the calix[4]­arene ring, this interaction could possibly be the formation of inclusion compounds upon interaction between the aromatic ring of the studied dinitrobenzenes and the calix[4]­arene moiety, though this process was discarded as the peak current did not decrease (as expected from the change in diffusion coefficients), and the potential shifts would take place in the opposite direction as expected for this reaction . Therefore, the experimental results indicate the presence of specific interactions between electrogenerated dianionic species and (HD) 2 -R 2 via ETCHB ,,,, following the mechanism described in eqs –.…”

An Electrochemical Approach for the Cucurbit[7]uril/Carbendazim Supramolecular Inclusion Complex. Application to Carbendazim Determination in Apples

“…Therefore, the complex formation mechanism is quite different for each family. Both can host nonpolar or relatively polar compounds in their hydrophobic cavity; however, unlike CDs, CB[n]s also can form complexes with ions or charged molecules through their polar portals and the binding constants reported for CB[n] complexes are usually higher than those for CDs [10].…”

“…Although this reaction was first reported in 1905 by Behrend et al [1] for the synthesis of CB [6], the structure of this CB was not described until 1981 by Mock et al [2]. Two decades later, Kim et al reported the synthesis of different CB[n]s homologues such as CB [5], CB [7] and CB [8] [3], although the mechanism and optimal conditions for that synthesis process were studied by Day [4] in order to improve the yields of isolated CB[n]s, including CB [10], at this time. The complex formation properties of the different CB[n]s have been also described [5,6].…”

“…For this reason, in recent years a large number of articles have reported CB[n] complex formation with different metal ions and organic compounds containing amine groups and charged amines, among others [7,8]. In some cases, binding constants up to 10 15 M À1 (similar to the value for avidin-biotin) have been reported [9]. Although the cavity sizes of some CB[n]s (n = 6-8) are comparable to a-, b-and g-CDs respectively, the properties of the two macrocyclic receptor families are significantly different.…”