Compared to structurally related linear trialkylamines, a simple macrocyclic amine with an anion-binding cavity exhibits very large rate enhancements (>10(5)) for stoichiometric N-alkylation with primary alkyl, allyl, and benzyl halides in the weakly polar solvent CDCl3. There is also a major distortion of the halide leaving-group order. For example, with benzyl halides the relative leaving-gro...

Abstract: Anions play an important role in a wide range of chemical and biological processes. Extensive attention has been focused on the design of hosts that can recognize and sense anion species selectively. Such recognition behavior can be monitored through optical, electrochemical, and fluorescence responses. The binding of an anion with a synthetic receptor is typically labile and reversib...

The zeroth-order regular approximation ~ZORA! is used for the evaluation of the electric field gradient, and hence nuclear quadrupole coupling constants, in some closed shell molecules. It is shown that for valence orbitals the ZORA-4 electron density, which includes a small component density ~‘‘picture-change correction’’!, very accurately agrees with the Dirac electron density. For hydrogen-l...

Distribution of electrolyte ions near the surface of water or ice is a subject of interest in both fundamental chemistry and atmospheric chemistry of sea-salt aerosols and ice particles. The ion distribution at the surface of these particles may affect their reaction with ozone and organic species in the troposphere and the generation of reactive halogen species. 2] In early studies, the surfac...

A ligand free, copper-catalyzed N-arylation reaction of amines with diheteroaryl halides in heterogeneous medium at room temperature has been developed. The protocol is very effective for low boiling amines and useful for amines available in aqueous solution. The reaction gives chemospecific arylation of amines with diheteroaryl halides in the mixture monoheteroaryl halides, diheteroaryl halide...

Due to their high electron density, fluoride anions can be considered the most effective halogen bond (HaB) acceptors among halides. However, under common experimental conditions, Fˉ is hardly available as dry species. Herein we report that specific crystallization conditions a hydrogen bond-free functioning donor of density obtained, with formed HaBs constituting driving force observed crystal...