The halogen bond occurs when there is evidence of a net attractive interaction between an electrophilic region associated with a halogen atom in a molecular entity and a nucleophilic region in another, or the same, molecular entity. In this fairly extensive review, after a brief history of the interaction, we will provide the reader with a snapshot of where the research on the halogen bond is now, and, perhaps, where it is going. The specific advantages brought up by a design based on the use of the halogen bond will be demonstrated in quite different fields spanning from material sciences to biomolecular recognition and drug design.

The Halogen Bond

9.2. Protein-Based Hg(II) Detectors 3467 9.3. Oligonucleotide-Based Hg(II) Detector 3467 9.4. DNAzyme-Based Hg(II) Detectors 3469 9.5. Antibody-Based Hg(II) Detector 3469 10. Mercury Detectors Based on Materials 3469 10.1. Soluble and Fluorescent Polymers 3469 10.2. Membranes, Films, and Fibers 3471 10.3. Micelles 3473 10.4. Nanoparticles 3473 11. Perspectives 3474 12. Addendum 3475 12.1. Small Molecules 3475 12.2. Biomolecules 3477 12.3. Materials 3477 13. List of Abbreviations 3477 14. Acknowledgments 3478 15. References 3478

Tools and tactics for the optical detection of mercuric ion.

A water-soluble turn-on fluorescent sensor for Hg(II) is described Incorporation of soft thioether donors into an aniline-derived ligand framework that can be linked to a fluorescein platform affords sensor MS1, which shows a approximately 5-fold increase in integrated emission upon addition of 1 equiv of Hg(II) The synthesis and metal-binding properties of MS1 are discussed, and its ability to detect environmentally relevant concentrations of Hg(II) is demonstrated

A "turn-on" fluorescent sensor for the selective detection of mercuric ion in aqueous media.

This critical review describes how halocarbons can function as effective binding sites of anions via halogen bonding, the noncovalent interaction whereby halogen atoms accept electron density. The focus is on the binding and coordination of oxyanions, by far the most numerous class of anions in organic chemistry. It is shown how a large variety of inorganic and organic oxyanions can form discrete adducts and 1D, 2D, or 3D supramolecular networks with chloro-, bromo-, and iodocarbons. Specific examples are discussed in order to identify new supramolecular synthons based on halogen bonding and to outline some general principles for the design of effective and selective receptors based on this interaction. The interaction allows for several other anions to self-assemble with halocarbons and mention is also given to the halogen bonding-based coordination of halides, polycyano- and polyoxometallates (72 references).

Halogen bonding: a general route in anion recognition and coordination

Electron transfer by copper centers.

A series of branched amino polythiaether multidentate ligands has been synthesized involving one or two tertiary amine nitrogen donor atoms to which are appended alkyl chains containing thiaether sulfur donors. The resulting compounds are analogous to the amino polycarboxylate reagents EDTA and NTA. Ligand protonation constants, Cu(II) complex stability constants, and Cu(II) complex formation rate constants have been determined.

Kinetic and thermodynamic measurements on branched amino polythiaether ligands: a family of complexing agents analogous to EDTA and NTA exhibiting enhanced selectivity for copper(II)

Effect of Ligand Constraints upon the Stabilities and Potentials of Macrocyclic Polythiaether Complexes. Copper(II) and Copper(I) Complexes with Cyclohexyl and Phenyl Derivatives of [14]aneS4 in Water, 80% Methanol, and Acetonitrile

Michael J. Mayer

Papers

Kinetic and thermodynamic measurements on branched amino polythiaether ligands: a family of complexing agents analogous to EDTA and NTA exhibiting enhanced selectivity for copper(II)

Effect of Ligand Constraints upon the Stabilities and Potentials of Macrocyclic Polythiaether Complexes. Copper(II) and Copper(I) Complexes with Cyclohexyl and Phenyl Derivatives of [14]aneS4 in Water, 80% Methanol, and Acetonitrile

Nickel(II) chelation by three bicyclic tetrathioethers : solution and solid-state data