Examining the Scope and Thermodynamics of Assembly in Nesting Complexes Comprising Molecular Baskets and TPA Ligands

Abstract

Molecular baskets capture various tris(2-pyridylmethyl)amine ligands, with and without zinc(II) cation, to form nesting complexes. The results of our computational (MD) and experimental (H NMR/ITC) studies suggest that the assembly is driven by the hydrophobic effect with the charge of complementary molecular components playing an important role in the formation of nesting complexes. In brief, the complexation only takes place when the basket and the ligand carry either oppositely charged or noncharged groups.

On the encapsulation and assembly of anticancer drugs in a cooperative fashion

“…The formation of binary 1 6– ⊂ 2 + is a favourable process ( K 1 = 3.2 ± 0.8 × 10 5 M –1 ) supported with the notion that the basket's top grips onto the drug by using all three of its phthalimide arms and engaging in five favourable non-covalent interactions (Fig. 5A): the top cavity shrinks to hold the drug, while the bottom one expands; the hydrophobic effect is expected to contribute to this complexation as well 42. With all three of the top cavity's sides being “tied”, the bottom three phthalimides become more rigid25 a and thus more preorganized to, via favourable entropy, increase the affinity for the second drug molecule ( K 2 = 9 ± 1 × 10 6 M –1 ).…”

Molecular Recognition of Nerve Agents and Their Organophosphorus Surrogates: Toward Supramolecular Scavengers and Catalysts

“…On the basis of calorimetry measurements (ITC), the complexation of neutral guests was driven by enthalpy (ΔH°< 0) suggesting a displacement of high energy water molecules from basket's inner space. [117] From the results of NMR measurements, both DMMP and DMPP were found to anchor their methoxy instead of PÀ CH 3 groups in the aromatic cavity of [12] 3 + . Evidently, baskets [10] 3 + /[11] 3À /[12] 3 + , with the same aromatic pocket, but different groups at the rim, use CÀ H … π contacts to hold onto OPs with the hydrophobic effect serving as the driving force in the complexations.…”

Control and Transfer of Chirality Within Well-Defined Tripodal Supramolecular Cages

“…Interestingly, this study allowed the authors to demonstrate that a predictable control of the helical arrangement of TPA-based complexes, could be achieved by an ionic contract-based transfer of chirality. In 2017, the same group further exemplified the approach by studying the capture of several metallated and non-metallated TPA derivatives by both anionic and cationic molecular baskets (Zhiquan et al, 2017 ).…”