A detailed study of the thermodynamics of the halogen-bonding interaction in organic solution is presented. (19)F NMR titrations are used to determine association constants for the interactions of a variety of Lewis bases with fluorinated iodoalkanes and iodoarenes. Linear free energy relationships for the halogen bond donor ability of substituted iodoperfluoroarenes XC(6)F(4)I are described, demonstrating that both substituent constants (sigma) and calculated molecular electrostatic potential surfaces are useful for constructing such relationships. An electrostatic model is, however, limited in its ability to provide correlation with a more comprehensive data set in which both halogen bond donor and acceptor abilities are varied: the ability of computationally derived binding energies to accurately model such data is elucidated. Solvent effects also reveal limitations of a purely electrostatic depiction of halogen bonding and point to important differences between halogen bonding and hydrogen bonding.

It′s in the I′s: Three suitably oriented electron‐deficient iodoaryl groups form the basis for the first anion receptor (see structure; white H, gray C, red O, blue F, purple I, green Cl) that employs the halogen‐bonding interaction alone to achieve high‐affinity molecular recognition in dilute solution. The anion selectivity of this tridentate host differs from those of similar receptors based on hydrogen bonding.

The interactions of iodoperfluoroarenes and -alkanes with anions in organic solvent were studied. The data indicates that favorable halogen-bonding interactions exist between halide anions and the monodentate model compounds C(6)F(5)I and C(8)F(17)I. These data served as a basis for the development of preorganized multidentate receptors capable of high-affinity anion recognition. Several new receptor architectures were prepared, and the multidentate-iodoperfluorobenzoate-ester design, as described in a preliminary communication, was evaluated in more detail. Computation was employed to better interpret the structure-activity relationships arising from these studies. Investigations of the thermodynamics of anion binding (by van't Hoff analysis) and solvent effects reveal details of these halogen bonding interactions.

Drei passend orientierte elektronenarme Iodarylgruppen bilden die Grundlage des ersten Anionenrezeptors (siehe Bild; weiß H, grau C, rot O, blau F, lila I, grün Cl), der ausschließlich Halogenbrücken verwendet, um eine hochaffine molekulare Erkennung in verdünnter Lösung zu erzielen. In seiner Anionenselektivität unterscheidet sich der Rezeptor von strukturverwandten Wasserstoffbrückenrezeptoren.

A palladium-catalyzed synthesis of acyl pyrroles from aryl and alkenyl iodides is reported. This carbonylative amination requires only atmospheric (balloon) pressure of carbon monoxide and proceeds with Pd(PPh(3))(4) and Pd-NHC catalysts. Aryl and heteroaryl iodides give the corresponding acyl pyrroles in good to excellent yields, while alkenyl iodides provide the corresponding acyl pyrroles in low to moderate yields.