Anion recognition chemistry has grown from its beginnings in the late 1960s with positively charged ammonium cryptand receptors for halide binding to, at the end of the millennium, a plethora of charged and neutral, cyclic and acyclic, inorganic and organic supramolecular host systems for the selective complexation, detection, and separation of anionic guest species. Solvation effects and pH values have been shown to play crucial roles in the overall anion recognition process. More recent developments include exciting advances in anion-templated syntheses and directed self-assembly, ion-pair recognition, and the function of anions in supramolecular catalysis.

Anion Recognition and Sensing: The State of the Art and Future Perspectives

Metal Complexes as Photo- and Radiosensitizers

Pyrrolic and polypyrrolic anion binding agents

Sapphyrin was the first expanded porphyrin to be reported in the literature and remains among the most extensively studied. Much of the interest in this macrocycle reflects its ability to bind anions, a phenomenon that has been examined in solution and in the solid state by a wide range of experimental techniques. In this Account, we summarize these studies while also outlining strategies that may be used to synthesize sapphyrins.

Sapphyrins: versatile anion binding agents.

The chemistry of expanded porphyrins, which are higher homologues of porphyrins, has been intensively explored for the last three decades. Expanded porphyrins exhibit structures, electronic properties, coordination chemistry, and reactivities that are entirely different from those of porphyrins. Through these studies, it has become increasingly apparent that expanded porphyrins are attractive in views of aromaticity and multimetal coordination, or as functional dyes, nonlinear optical materials, ion receptors, or stable organic radicals. As such, we have continuously witnessed the emergence of expanded porphyrins that exhibit unprecedented structures and properties, as is highlighted by the facile realization of Mobius aromatic and even antiaromatic systems with twisted molecular structures. In this Review, the recent progress of the chemistry of expanded porphyrins after the seminal Review by Sessler and Seidel in 2003 is presented.

Francis Laurie. Harris

Papers

Sapphyrins: novel aromatic pentapyrrolic macrocycles

Macro rings. XXXV. Stereochemistry of [2.2]paracyclophanyl nucleus as a neighboring group in solvolyses reactions

Sapphyrins: novel aromatic pentapyrrolic macrocycles