An 'ensemble'-based fluoregenic chemodosimeter 1-Cu(II) for detection of thiols is reported. Complex 1-Cu(II) sensitively senses thiols followed by hydrolysis to give a marked fluorescence enhancement over other amino acids at pH 7.4 under aqueous media. Confocal microscopic imaging of complex 1-Cu(II) is also herewith demonstrated for cellular thiol detection in HepG2 cells.

Chiral inversion of single molecules has been a challenging task because chirality information controls structures and functions of various molecules, artificial nanostructures, DNA, and proteins. Herein we present a pseudo[1]catenane-type molecule whose planar chiral inversion is driven by a metal ion under the control of anions for the first time. Considering an in-out equilibrium of a fused thiacrown and the soft metal binding, pillar[5]thiacrown ( rac-L) was synthesized. Two planar-chiral enantiomers of rac-L ( in-pS-L and in-pR-L) were isolated and the absolute configuration was determined by circular dichroism and single crystal X-ray analysis. The in-pS-L recognizes Hg to trigger the chiral inversion to out-pR-L, to our surprise; it takes place only in the presence of ClO or NO among the anions used. In the mercury(II) perchlorate complex solution, anion-exchange from ClO to I or removal of Hg by addition of S makes the system reversible. The crystallographic approach reveals that the anions act as coordination mode-directing species ( endo- or exo-coordination) which play a decisive role on the chiral inversion. For instance, the week coordinating ClO allows Hg to locate inside the thiacrown ( endo-coordination) which causes the chiral inversion from in-pS-L to out-pR-L due to the expansion of the thiacrown unit upon endo-mode complexation. Oppositely, the strong coordinating I takes Hg out of the thiacrown ( exo-coordination) without large conformational changes of the thiacrown, resulting in no chiral inversion. A series of experimental works was also accomplished with the other enantiomer in-pR-L, which afforded identical results. Consequently, the chiral inversion is governed by steric factors that arise from the coordination modes depending on the coordinating ability of anions. This work demonstrates the first chiral inversion induced by combination of metal ion and anion and presents a new perspective on the supramolecular coordination chemistry of pillar[ n]arenes.

Tetra-armed cyclens bearing aromatic side arms were prepared by the reductive amination of cyclen with substituted benzaldehydes. When equimolar amounts of Ag(+) ions were added to the ligands, the aromatic rings covered the Ag(+) ions incorporated in the ligand cavities, as if the aromatic ring "petals" caught the Ag(+) ions in the way an insectivorous plant (Venus flytrap) catches insects. The ligands are called "argentivorous molecules". Evidence of intramolecular Ag(+)-π interactions in solution and in the solid state is reported.

A one‐pot reaction of the A1/A2‐thiopyridyl pillar[5]arene L with silver(I) trifluoroacetate in the presence of the linear dinitrile guest C8, [CN(CH2)nCN, n=8], afforded the first example of a two‐dimensional (2D) poly‐pseudo‐rotaxane {[(μ4‐Ag)2(C8@L)2(μ‐C8)](CF3CO2)2}n. Surprisingly, in this structure the C8 guest not only threads into the pillar[5]arene unit but also crosslinks the 1D coordinative polymeric arrays. The formation of the 2D poly‐pseudo‐rotaxane is driven by an adaptive rearrangement of the components that minimizes the steric clashes not only between the threaded guests but also between the threaded and crosslinked guests where crosslinking occurs. A pathway for the formation of the 2D poly‐pseudo‐rotaxane is proposed.

Seven double-armed cyclens bearing two aromatic side-arms, at the 1- and 7-positions of the cyclens, were prepared via three steps from dimethyl 2,2'-iminodiacetate. The X-ray structures of the Ag(+) complexes and Ag(+)-ion-induced (1)H NMR spectral changes suggest that the two aromatic side-arms cover the Ag(+) ions incorporated in the ligand cavities, as if the aromatic ring "petals" catch the Ag(+) ions in the way a real insectivorous plant (Venus flytrap) catches insects, using two leaves. It is also reported that the CH-π interactions between the aromatic side-arms, as well as the Ag(+)-π interactions, are crucial for double- and tetra-armed cyclens to work as argentivorous molecules.