Helical nanofibers of N-(perfluorooctanoyl)cysteine ethyl ester in coordination polymers of Ag. Chem Commun (Camb) 2020;56:15133-15136. [PMID: 33165457 DOI: 10.1039/d0cc05989g]

Metallo-Supramolecular Helical Fibres from Chiral Phenylacetylene Monomers: Cation Induced Self-Assembly

Chiral metallo-supramolecular fibres can be easily obtained by mixing a chloroform solution of a phenylacetylene monomer (PA) that bears a chiral sulfoxide group as pendant, with different equivalents of a methanolic solution of AgClO4 . Thus, while the PA is found molecularly dissolved in chloroform, the addition of Ag+ ions induce its aggregation through the formation of an axially chiral metallo-supramolecular aggregate with high thermal stable properties. In this case, the ability of the metal ion to coordinate the PA triple bond, combined with the argentophilicity of the metal ion and the planarity of the phenylacetylene drives to the formation of a helical coordination polymer, whose P or M axial chirality is determined by the chirality of the sulfoxide used as substituent of the PA. Depending on the PA/Ag+ (mol/mol) ratio, it is possible to tune the morphology of the metallo-supramolecular aggregate from chiral fibers to chiral gel.

Aggregated coordination polymers of Ag+ with a cysteine derivative ligand containing an AIEgen

We investigated coordination polymers of Ag⁺ with a cysteine-based thiol ligand designed to contain a tetraphenylethylene AIEgen (L- and D-1). The coordination polymers, forming in a variety of protic and aprotic organic solvents, such as THF, CH₃CN and CH₃OH, were shown to undergo aggregation in H₂O/THF binary solvents at water volume fractions above 50%, where emission was substantially enhanced while the CD profile was reversed, yet the dependence of the CD signal on ee remained S-shaped for the polymers in the aprotic organic solvents THF and CH₃CN, in contrast to that in protic solvents CH₃OH and C₂H₅OH.

Self-Assembled Multivalent Ag-SR Coordination Polymers with Phosphatase-Like Activity

We show herein the phosphatase-like catalytic activity of coordination polymers obtained after adding Ag⁺ -ions to thiols bearing hydrophobic alkyl chains terminated with a 1,4,7-triazacyclononane (TACN) group. The subsequent addition of Zn²⁺ -ions to the self-assembled polymers resulted in the formation of multivalent metal coordination polymers capable of catalysing the transphosphorylation of an RNA-model compound (2-hydroxypropyl-4-nitrophenyl phosphate, HPNPP) with high reactivity. Analysis of a series of metal ions showed that the highest catalytic activity was obtained when Ag⁺ -ions were used as the first metal ions to construct the backbone of the coordination polymer through interaction with the -SH group followed by Zn²⁺ -ions as the second metal ions complexed by the TACN-macrocycle. Furthermore, it was demonstrated that the catalytic activity could be modulated by changing the length of the hydrophobic alkyl chain.

Solvophobic interaction promoted supramolecular helical assembly of building blocks of weak intermolecular halogen bonding

Bromination of β-turn structured bis(N-amidothiourea) facilitates the formation of supramolecular helical polymers in water through halogen bonding and hydrophobic interaction, exhibiting an unusual negative nonlinear CD-ee dependence.

Nanospheres from coordination polymers of Ag+ with a highly hydrophilic thiol ligand formed in situ from dynamic covalent binding and a hydrophobic thiol

A supramolecular nanosphere with a diameter of 8.7 nm is obtained in an aqueous alkaline solution via glucose binding to a boronic acid-based thiol (4-MPBA) as a hydrophilic ligand, together with a hydrophobic thiol ligand n-C8H17SH.