Capture and Release of [PdCl₄]^2– by TMeQ[6]-Based Supramolecular Frameworks Assembled via the Outer Surface Interaction of Q[n]s

Abstract

TMeQ[6] exhibits high selectivity for [PdCl 4 ] 2− anion in an HCl solution to form supramolecular frameworks via the anion-induced outer-surface interactions of cucurbit[n]urils. However, in an HNO 3 solution, TMeQ[6] can only form metal free supramolecular frameworks via the self-induced outer-surface interactions of cucurbit[n]urils. Using these properties, a process for collecting and recovering precious palladium could be established.

Supramolecular Self‐Assembly Modes of Cyclopentanocucurbit[6]uril and Aromatic Amines

“…For host-guest encapsulation, the portal and outer-surface interactions are common modes observed in Q[n]. [22][23][24][25] During the selection of the guest molecule, small molecules comprised of aromatic amines have become a hotspot for supramolecular assembly because their amino groups are easily protonated under acidic conditions and the CÀ H⋅⋅⋅π interactions makes it easier for the benzene ring to interact with Q[n]. [26,27] Therefore, many researchers have studied the interaction of modified Q[n] with aromatic amines.…”

Supramolecular Host‐Guest Interaction‐Driven Electrochemical Recognition for Pyrophosphate and Alkaline Phosphatase Analysis

“…There are two main factors: (1) the high-energy water captured in CB[n] cavity is released so as to lead to non-classical hydrophobic effect; (2) the electron-rich carbonyl portals of CB[n] is preferable binding with some guest molecules with positive charges due to the typical electrostatic attraction. [35,36] Among the family of CB[n]s, CB [7] can combine harmoniously with the majority of guest molecules owing to its low cytotoxicity and good aqueous dispersity. [37,38] For example, this cooperation between cavity and portal in CB [7] has been demonstrated to bind well with some special peptides (phenylalanine (Phe), tryptophan (Trp), tyrosine (Tyr), etc.).…”

“…Why is there a strong host‐guest complexation force between CB[n] and certain molecule? There are two main factors: (1) the high‐energy water captured in CB[n] cavity is released so as to lead to non‐classical hydrophobic effect; (2) the electron‐rich carbonyl portals of CB[n] is preferable binding with some guest molecules with positive charges due to the typical electrostatic attraction [35,36] . Among the family of CB[n]s, CB[7] can combine harmoniously with the majority of guest molecules owing to its low cytotoxicity and good aqueous dispersity [37,38] .…”