Noncovalent interactions play an important role in many biological and chemical processes. Among these, hydrogen bonding is very well studied and is already routinely used in organocatalysis. This Short Review focuses on three other types of promising noncovalent interactions. Halogen bonding, chalcogen bonding, and anion-π bonding have been introduced into organocatalysis in the last few years...

The isomeric derivatives 1,2-bis-(iodo-meth-yl)benzene, (I), and 1,3-bis-(iodo-meth-yl)benzene (II), both C8H8I2, were prepared by metathesis from their di-bromo analogues. The ortho-derivative, (I), lies about a crystallographic twofold axis that bis-ects the C-C bond between the two iodo-methyl substituents. The packing in (I) relies solely on C-H⋯I hydrogen bonds supported by weak parallel s...

In the title compound, C(15)H(10)BrFO(2)S, the O atom and the methyl group of the methyl-sulfinyl substituent lie on opposite sides of the plane through the benzofuran fragment. The 4-bromo-phenyl ring is rotated out of the benzofuran plane [dihedral angle = 38.98 (8)°], while the structure is stabilized by an inter-molecular C-H⋯O hydrogen bond and a Br⋯O halogen bond [3.036 (2) Å] and has an ...

A thorough search of the potential energy surface is carried out for heterodimers of water with C2ClnF4n. Three different types of interactions are observed. Structures dominated by a lone pair-π interaction have the highest binding energies, and are stabilized by charge transfer from O lone pairs of H2O to the C-C π* antibonding orbital of the alkene. Halogen-bonded O··Cl complexes are slightl...

The structure of the title salt, (C9H7IN)[AuCl4], is comprised of planar 8-iodo-quinolinium cations (r.m.s. deviation = 0.05 Å) and square-planar tetra-chlorido-aurate(III) anions. The asymmetric unit contains one 8-iodo-quinolinium cation and two halfs of [AuCl4](-) anions, in each case with the central Au(III) atom located on an inversion center. Inter-molecular halogen-halogen contacts were ...

Halogen bonds are shown to possess the same characteristics as hydrogen bonds: charge transfer, resonance assistance and cooperativity. This follows from the computational analyses of the structure and bonding in N-halo-base pairs and quartets. The objective was to achieve an understanding of the nature of resonance-assisted halogen bonds (RAXB): how they resemble or differ from the better unde...

The combination of H2C═NH and cis-1,3-butadiene to form a six-membered ring was examined by quantum calculations. The energy barrier for this reaction is substantially lowered by the introduction of an imidazolium catalyst with either a H or halogen (X) atom in the 2-position, which acts via a H or halogen bond to the N atom of the imine, respectively. X = I has the largest effect, and Cl the s...

Besides the most common form of aromaticity involving a π-ring, hexaiodobenzene and hexakis(phenylselenyl)benzene dications also present σ-aromaticity in outer ring formed by main group substituents. These two compounds are considered σ- π-double aromatic, their characterization is special interest to fields organic structural chemistry. In this work, we decided explore double substituted tropy...