background: reduced time and appropriate bond strength of brackets is one of the most important aspects of orthodontic treatments. prolonged halogen light curing for bonding of brackets is undesirable, so the purpose of this study was to compare the shear bond strength of brackets bonded with halogen light and plasma arc system. materials and mehods: this was an experimental in vitro study. a t...

The use of halogen bond is widespread in drug discovery, design, and clinical trials, but is overlooked in drug biosynthesis. Here, the role of halogen bond in the nitrilase-catalyzed synthesis of ortho-, meta-, and para-chlorophenylacetic acid was investigated. Different distributions of halogen bond induced changes of substrate binding conformation and affected substrate selectivity. By engin...

In this paper, ab initio calculations were performed on the ternary complex formed by HB(CO)2, XCN (X = Cl, Br) and YF (Y = Li, H, Cl). In these complexes boron act as a non-classical electron donor to form a unconventional halogen bond. The cooperative effect between the B•••X halogen bond and lithium/hydrogen/halogen bond was investigated. The calculated results show that the B•••X and N•••Y ...

There has recently been an increasing interest in controlling macromolecular conformations and interactions through halogen bonding. Halogen bonds are favorable electrostatic interactions between polarized, electropositive chlorine, bromine, or iodine atoms and electronegative atoms such as oxygen or nitrogen. These interactions have been likened to hydrogen bonds in terms of their favored acce...

Halogen bonding is a weak chemical force that has so far mostly found applications in crystal engineering. Despite its potential for use in drug discovery, as a new molecular tool in the direction of molecular recognition events, it has rarely been assessed in biopolymers. Motivated by this fact, we have developed a peptide model system that permits the quantitative evaluation of weak forces in...

The formation of a halogen bonded self-assembled co-crystal physisorbed monolayer containing N···Br interactions is reported for the first time. The co-crystal monolayer is identified experimentally by synchrotron X-ray diffraction and the structure determined. Density functional theory (DFT) calculations are also employed to assess the magnitudes of the different interactions in the layer. Sig...

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 n...

the character of the intermolecular interactions in cl2-hx (x =f, cl and br) complexes has been investigated by means of the second-order möller–plesset perturbation theory (mp2) and the density functional theory (dft) calculations. the results show that there are two types of lowest interaction potential equilibrium structures in the interactions between cl2 and hx: x∙∙∙cl type geometry and hy...

Halogen bonding is an emerging noncovalent interaction for constructing supramolecular assemblies. Though similar to the more familiar hydrogen bonding, four primary differences between these two interactions make halogen bonding a unique tool for molecular recognition and the design of functional materials. First, halogen bonds tend to be much more directional than (single) hydrogen bonds. Sec...