To Loop or Not to Loop: Influence of Hinge Flexibility on Self-Assembly Outcomes for Acridine-Based Triazolylpyridine Chelates with Zinc(II), Iron(II), and Copper(II).

Coordination-driven self-assembly has been established as an effective strategy for the efficient construction of intricate architectures in both natural and artificial systems, for applications ranging from gene regulation to metal-organic frameworks. Central to these systems is the need for carefully designed organic ligands, generally with rigid components, that can undergo self-assembly with metal ions in a predictable manner. Herein, we report the synthesis and study of three novel organic ligands that feature 3,6-disubstituted acridine as a rigid spacer connected to two 2-(1,2,3-triazol-4-yl)pyridine "click" chelates through hinges of the same length but differing flexibility.

Closing the Loop: Triazolylpyridine Coordination Drives the Self-Assembly of Metallomacrocycles with Tunable Topologies for Small-Molecule and Guanine-Quadruplex Recognition.

The 2-(1,2,3-triazol-4-yl)pyridine motif, with its facile "click" synthesis and remarkable coordinative properties, is an attractive chelate for applications in the metal-directed self-assembly of intricate three-dimensional structures. Organic ligands that bear two such chelates bridged by flexible hinge moieties readily undergo self-assembly with metal ions of different coordination geometries to generate a series of topologically diverse metallomacrocycles that can be used for numerous applications. Herein, the synthesis and self-assembly of one such ligand with zinc(II), copper(II), and palladium(II) ions is reported, and the stability of the resulting metallomacrocycles described.

Systematic study of the synthesis and coordination of 2-(1,2,3-triazol-4-yl)-pyridine to Fe(II), Ni(II) and Zn(II); ion-induced folding into helicates, mesocates and larger architectures, and application to magnetism and self-selection.

With its facile synthesis, the pyridine-1,2,3-triazole chelate is an attractive building block for coordination-driven self-assembly. When two such chelates are bridged by a spacer and exposed to cations of octahedral geometrical preference, they generally self-assemble into dinuclear triple-stranded structures in the solid state and in solution in the presence of non-coordinating counter-ions. In solution, a wider range of architectures may nevertheless form, depending on the nature of the spacer.

Click-triazole: coordination of 2-(1,2,3-triazol-4-yl)-pyridine to cations of traditional tetrahedral geometry (Cu(I), Ag(I)).

Coordination studies of the pyridine-triazole diad to copper(i) and silver(i) reveal the potential and conditions for the solution- and solid-state self-assembly of supramolecular architectures based on this motif.

Nuclear magnetic resonance studies on covalent modification of amino acids thiol and amino residues by monofunctional aryl 13C-isocyanates, models of skin and respiratory sensitizers: transformation of thiocarbamates into urea adducts.

Exposure to aryl isocyanates, intermediates in the manufacture of polyurethanes, provokes lung sensitization and asthma but also occupational allergic contact dermatitis, sensitization occurring from a single accidental exposure. The initial step in the sensitization process is believed to be the covalent binding of the -N triple bond C triple bond O group with nucleophilic residues on proteins. While a wide knowledge exists on the reactivity of skin sensitizers toward amino acids, little is known about respiratory sensitizers such as aryl isocyanates.