There is great need for stand-alone luminescence-based chemosensors that exemplify selectivity, sensitivity, and applicability and that overcome the challenges that arise from complex, real-world media. Discussed herein are recent developments toward these goals in the field of supramolecular luminescent chemosensors, including macrocycles, polymers, and nanomaterials. Specific focus is placed on the development of new macrocycle hosts since 2010, coupled with considerations of the underlying principles of supramolecular chemistry as well as analytes of interest and common luminophores. State-of-the-art developments in the fields of polymer and nanomaterial sensors are also examined, and some remaining unsolved challenges in the area of chemosensors are discussed.

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Supramolecular Luminescent Sensors

Colorimetric metal ion sensors – A comprehensive review of the years 2011–2016

Among the recent developments in metal-organic frameworks (MOFs), porous layered coordination polymers (CPs) have garnered attention due to their modular nature and tunable structures. These factors enable a number of properties and applications, including gas and guest sorption, storage and separation of gases and small molecules, catalysis, luminescence, sensing, magnetism, and energy storage and conversion. Among MOFs, two-dimensional (2D) compounds are also known as 2D CPs or 2D MOFs. Since the discovery of graphene in 2004, 2D materials have also been widely studied. Several 2D MOFs are suitable for exfoliation as ultrathin nanosheets similar to graphene and other 2D materials, making these layered structures useful and unique for various technological applications. Furthermore, these layered structures have fascinating topological networks and entanglements. This review provides an overview of different aspects of 2D MOF layered architectures such as topology, interpenetration, structural transformations, properties, and applications.

Two-Dimensional Metal-Organic Framework Materials: Synthesis, Structures, Properties and Applications.

Pillararenes as macrocyclic hosts: a rising star in metal ion separation.

The combination of the copper(i)-iodide entity with organic ligands gives rise to a large variety of CuII polynuclear structures in the form of molecular complexes or extended structures. An appropriate selection of these components allows the preparation of materials showing interesting physicochemical properties and potential applications, mainly focused on organic light-emitting diodes and optical sensors. The most prominent physical feature of these materials is their emission, which can be modulated using the chemical structure and composition. This review article collates the advances in this research field, rationalizing the information into two main blocks as a function of the dimensionality of the structures: molecular complexes and extended networks. We describe the most typical ways of preparation, structures, and properties, with particular attention to the processability of the material as a fundamental aspect of the integration of the materials into real devices. Therefore, we aim to integrate the basic elements of the coordination chemistry of CuII clusters from the materials science perspective to envision this promising research field's potential technological future.

Copper(i)-iodide cluster structures as functional and processable platform materials.

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 )n CN, n=8], afforded the first example of a two-dimensional (2D) poly-pseudo-rotaxane {[(μ4 -Ag)2 (C8@L)2 (μ-C8)](CF3 CO2 )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.

Formation of a Pillar[5]arene-Based Two-Dimensional Poly-Pseudo-Rotaxane: Threading and Crosslinking by the Same Guest Molecules.

Recent developments in the thiamacrocyclic chemistry of the latter d-block elements

A comparative study on the formation of guest clusters induced by different shapes (or sizes) of exocyclic binding sites embedded in the bis-macrocyclic host isomers is reported. CuI reacts with two regioisomers of a bis-dithiamacrocycle, o-bis-L (W-shaped binding site) and m-bis-L (U-shaped binding site), to yield one-dimensional coordination polymers {[(μ4-Cu4I4)(o-bis-L)]·2CH3CN}n (1a) and [(μ4-Cu2I2)(m-bis-L)]n (2). In 1a, the o-bis-L ligand isomer is linked by a spacious cubane [Cu4I4] cluster, while the m-bis-L ligand in 2 is linked by a smaller rhomboid [Cu2I2] cluster because of the different exocyclic binding sites. The results observed illustrate the possibility for the metal clusters including [CunIn] (n = 2 or 4) to adopt a controlled formation through the binding site alternation or design. Because of the adaptive cluster formations, the products show different photophysical properties. Additionally, sliding of the one-dimensional chains in 1a was observed upon loss of the lattice solvent mol...

Ligand-Induced Formation of Copper(I) Iodide Clusters: Exocyclic Coordination Polymers with Bis-dithiamacrocycle Isomers

We report how the metal cation and its counteranions cooperate in the complexation-based macrocyclic chemosensor to monitor the target metal ion via the specific coordination modes. The benzothiazolyl group bearing NO2S2-macrocycle L was synthesized, and its mercury(II) selectivity (for perchlorate salt) as a dual-probe channel (UV–vis and fluorescence) chemosensor exhibiting the largest blue shift and the fluorescence turn-off was observed. In the mercury(II) sensing with different anions, except ClO4– and NO3–, no responses for mercury(II) were observed with other anions such as Cl–, Br–, I–, SCN–, OAc–, and SO42–. A crystallographic approach for the mononuclear mercury(II) perchlorate complex [Hg(L)(ClO4)2]·0.67CH2Cl2 (1) and polymeric mercury(II) iodide complex [Hg(L)I2]n (2) revealed that the observed anion-controlled mercury(II) sensing in the fluorescence mainly stems from the endo- and exocoordination modes, depending on the anion coordinating ability, which induces either the Hg–Ntert bond format...

Cation-Selective and Anion-Controlled Fluorogenic Behaviors of a Benzothiazole-Attached Macrocycle That Correlate with Structural Coordination Modes.

Using an S-pivot joint flexible ligand bis(4-cyanobenzyl)sulfide (bcbs), three silver(I) complexes [Ag(bcbs)ClO4]n (1), [Ag2(bcbs) (CF3CO2)2]n (2), and {[Ag3(bcbs)4](PF6)3·4CH2Cl2}n (3) have been isolated. Configurations (“V”-, “L”-, and “W”-shapes) of the bcbs ligand in 1–3 can be tuned as a result of changing the anions of the silver(I) salts, which ultimately form a series of infinite low to high dimensional frameworks with different structures. The perchlorato compound 1 shows a stairway type 1-D ribbon structure, in which the anion acts as a monodentate terminal ligand. The bcbs ligand in 1 shows a gauche–anti arrangement, adopting an L-shape configuration. The π–π stacking interaction between adjacent ribbons in 1 yields a pseudo-2-D structure with a herringbone pattern. Compound 2 is composed of silver(I)–bcbs helical channels, which are further interlinked via monodentate bridging CF3CO2– ions forming a 3-D multichannel framework with a dmd topology. Unlike 1, the bcbs ligand in 2 shows an anti–an...

Seulgi Kim

Papers

Formation of a Pillar[5]arene-Based Two-Dimensional Poly-Pseudo-Rotaxane: Threading and Crosslinking by the Same Guest Molecules.

Recent developments in the thiamacrocyclic chemistry of the latter d-block elements

Ligand-Induced Formation of Copper(I) Iodide Clusters: Exocyclic Coordination Polymers with Bis-dithiamacrocycle Isomers

Cation-Selective and Anion-Controlled Fluorogenic Behaviors of a Benzothiazole-Attached Macrocycle That Correlate with Structural Coordination Modes.

Anion-Directed Coordination Networks of a Flexible S-Pivot Ligand and Anion Exchange in the Solid State