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The molecular recognition properties of two pillar[n]arene sulfates (P[5]AS and P[6]AS) toward a panel of world anti-doping agency banned substances (1 – 11) were investigated by a combination of isothermal titration calorimetry, 1H NMR spectroscopy, and molecular modelling. Subsequently a sensing ensemble based on indicator displacement was created using the P[5]AS•lucigenin and P[6]AS •Hoechst 33258 complexes which allowed differentiation among the analytes with 90% accuracy. The assay was extended to allow the quantitation of pseudoephedrine in simulated urine samples with a limit of quantitation that is 30-fold below the WADA threshold. 

We report the molecular recognition properties of Pillar[ n ]MaxQ (P[ n ]MQ) toward a series of (methylated) amino acids, amino acid amides, and post-translationally modified peptides by a combination of 1 H NMR, isothermal titration calorimetry, indicator displacement assays, and molecular dynamics simulations. We find that P6MQ is a potent receptor for N -methylated amino acid side chains. P6MQ recognized the H3K4Me 3 peptide with K d = 16 nM in phosphate buffered saline. 

We report an investigation of the complexation between a water soluble pillararene host (WP6) and a panel of hydrophobic cationic guests (G1–G20) by a combination of 1 H NMR spectroscopy and isothermal titration calorimetry in phosphate buffered saline. We find that WP6 forms 1 : 1 complexes with K a values in the 10 4 –10 9 M −1 range driven by favorable enthalpic contributions. This thermodynamic dataset serves as blinded data for the SAMPL9 challenge. 

Selective and site-specific boron-doping of polycyclic aromatic hydrocarbon frameworks often give rise to redox and/or photophysical properties that are not easily accessible with the analogous all-carbon systems. Herein, we report ligand-mediated control of boraphenanthrene closed- and open-shell electronic states, which has led to the first structurally characterized examples of neutral bis(9-boraphenanthrene) (2–3) and its corresponding biradical (4). Notably, compounds 2 and 3 show intramolecular charge transfer absorption from the 9-boraphenanthrene units to p-quinodimethane, exhibiting dual (red-shifted) emission in solution due to excited state conjugation enhancement (ESCE). Moreover, while boron-centered monoradicals are ubiquitous, biradical 4 represents a rare type of open-shell singlet compound with 95% biradical character, among the highest of any reported boron-based polycyclic species with two radical sites. 

A 3,5-bis((2-iodophenyl)ethynyl)pyridinium scaffold was synthesized which introduces the use of methanesulfonyl withdrawing groups to polarize iodine halogen bonding units for anion binding. We investigate the capability of this receptor to bind halides in polar media, while further probing the structure–property relationship of this well-polarized yet under-explored halogen bonding system. 

We have rationally designed and synthesized a library of phosphaquinolinone derivatives containing various electron-donating and -withdrawing groups on two positions of the scaffold. Distinct trends are observed between the substituents on R 1 and R 2 with both the photophysical properties of the molecules and their dimerization strengths. With withdrawing groups upon the scaffold, dimerization constants surpass 500 M −1 in H 2 O-saturated CDCl 3 . Computational studies on the dimeric structures corroborate the experimental findings. 

Abstract We describe two novel hybrid receptors combining a phosphorus‐/nitrogen‐containing (PN) phosphonamidate heterocycle with urea recognition units in an arylethynyl backbone. Structural, spectroscopic and computational studies reveal that the origin of superior binding for hydrogen sulfate (HSO₄⁻) anion is correlated with the formation of strong hetero‐complementary hydrogen bonds with the phosphonamidate motif. We further demonstrate that the hybrid host system is capable of capturing/transporting the HSO₄⁻anion from an aqueous, biphasic system.