Cucurbit[n]urils (CBn) are glycoluril‐based macrocyclic hosts that bind many biologically, medicinally and environmentally relevant analytes with record high affinities in aqueous media. They are therefore prime candidates for the design of chemosensors that are operational in biological fluids, waste and drinking water and have promising potential to be utilized for in vitro and in vivo sensing and imaging applications. Unlike protein‐based antibodies, CBn can be prepared in multi kilogram scales, they are chemically robust and they show a desired fast analyte‐binding kinetics. Unlike protein‐based antibodies, CBn can be prepared in multi kilogram scales, are chemically robust and show a desired fast analyte‐binding kinetics Selective analyte detection and differentiation is possible owing to the charge‐ and size‐selective binding characteristics of the CBn members and due to the wide range of cyclic and acyclic CBn derivatives that differ in their analyte binding preference. Because CBn hosts are spectroscopically silent in the visible electromagnetic spectrum, optical signal transduction with CBn based chemosensing ensembles is typically performed by indicator displacement assays (IDA), which are easy to implement and applicable to both aliphatic and aromatic analytes. The extension to array‐based sensing with CBn chemosensors is straightforward. Associative binding assays (ABA), which are uniquely available with CB8‐based self‐assembled receptors offer superior analyte differentiation possibility due to emerging spectral fingerprints in the absorbance, circular dichroism (CD) and emission spectra for the receptor•analyte complexes. Direct signal generation is promising for inherently spectroscopically active analytes, for instance through absorbance, CD, emission and surface enhanced Raman spectroscopy (SERS). Sensitive NMR (19F, 129Xe) techniques, electron spin resonance (ESR), redox, and mass spectrometry are also valuable signal transduction options for specific analytes. CBn based chemosensors were successfully utilized for the monitoring of biophysical processes and enzymatic reactions with label free analytes or substrates in real time. These applications capitalize on the fast equilibration kinetics of CBn‐analyte complexes and the bio‐compatibility of CBn hosts. The tabulated large body of data extracted from reported CBn‐based binding studies is hoped to provide the reader with a valuable starting point for designing practically applicable CBn‐based sensors.

A systematic series of heteroleptic bis(tridentate)ruthenium(II) complexes of click-derived 1,3-bis(1,2,3-triazol-4-yl)benzene N^C^N-coordinating ligands was synthesized, analyzed by single crystal X-ray diffraction, investigated photophysically and electrochemically, and studied by computational methods. The presented comprehensive characterization allows a more detailed understanding of the radiationless deactivation mechanisms. Furthermore, we provide a fully optimized synthesis and systematic variations towards redox-matched, broadly and intensely absorbing, cyclometalated ruthenium(II) complexes. Most of them show a weak room-temperature emission and a prolonged excited-state lifetime. They display a broad absorption up to 700 nm and high molar extinction coefficients up to 20 000 M(-1)cm(-1) of the metal-to-ligand charge transfer bands, resulting in a black color. Thus, the complexes reveal great potential for dye-sensitized solar-cell applications.

A series of heteroleptic bis(tridentate) ruthenium(II) complexes bearing ligands featuring 1,2,3-triazolide and 1,2,3-triazolylidene units are presented. The synthesis of the C^N^N-coordinated ruthenium(II) triazolide complex is achieved by direct C-H activation, which is enabled by the use of a 1,5-disubstituted triazole. By postcomplexation alkylation, the ruthenium(II) 1,2,3-triazolide complex can be converted to the corresponding 1,2,3-triazolylidene complex. Additionally, a ruthenium(II) complex featuring a C^N^C-coordinating bis(1,2,3-triazolylidene)pyridine ligand is prepared via transmetalation from a silver(I) triazolylidene precursor. The electronic consequences of the carbanion and mesoionic carbene donors are studied both experimentally and computationally. The presented complexes exhibit a broad absorption in the visible region as well as long lifetimes of the charge-separated excited state suggesting their application in photoredox catalysis and photovoltaics. Testing of the dyes in a conventional dye-sensitized solar cell (DSSC) generates, however, only modest power conversion efficiencies (PCEs).

In this study, we report the first supramolecular indicator displacement assay (IDA) based on cucurbit[n]uril (CBn) host and a [2.2]paracyclophane derivative as indicator that is operational in blood serum.

A series of bis(tridentate) ruthenium(II) complexes featuring new anionic 1,2,3-triazolate-based tridentate ligands and 2,2':6',2''-terpyridine is presented. For a complex equipped with carboxy anchoring groups, the performance in a dye-sensitized solar cell is evaluated. The title complexes are readily synthesized and can be decorated with alkyl chains utilizing azide-alkyne cycloaddition methods, in order to improve the device stability and allow the use of alternative electrolytes. On account of the strong electron donation from the 1,2,3-triazolates, the complexes exhibit a broad metal-to-ligand charge-transfer absorption (up to 700 nm), leading to an electron transfer toward the anchoring ligand. The lifetimes of the charge-separated excited states are in the range of 50 to 80 ns. In addition, the ground- and excited-state redox potentials are appropriate for the application in dye-sensitized solar cells, as demonstrated by power conversion efficiencies of up to 4.9% (vs 6.1% for N749).