Halogen Bonding beyond Crystals in Materials Science

Abstract

Halogen bonding has recently gained well deserved attention in present-day research for its importance in many fields of supramolecular science and crystal engineering. Although generally overlooked in comprehensive studies in the past, halogen bonding has become an important tool also in the field of materials science. An increased number of scientific reports are published every year where halogen bonding is exploited in soft materials rather than in crystal engineering. Here, we focus on a description of the most exciting contemporary developments in the field of halogen-bonded functional soft materials, assembled using the guiding principles of crystal engineering. We give a particular emphasis to those published in the past few years.

Halogen Bonding in Isostructural Co(II) Complexes with 2-Halopyridines

“…Regarding all of the approaches in the field of crystal engineering, halogen bonding (XB) has attracted great interest within modern research [1,2]. This type of non-covalent interaction involving halogen atoms (according to the IUPAC-approved definition, the 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") becomes especially prominent in a solid state, and its appearance can affect numerous physical properties of matter, such as luminescence [3][4][5], solubility [6], color [7], and so forth, therefore providing an additional tool for material design [8][9][10].…”

O–I–O halogen bond of halonium ions

“…1 It was first observed in 1863 by Guthrie, 2 but only began to receive significant attention towards the end of the 20th century. Today, halogen bonding is one of the fastest growing research topics in chemistry 3 with applications for example in crystal engineering, 4,5 drug design, [6][7][8][9] material sciences, [10][11][12] and organic synthesis. [13][14][15] A halenium ion 16 (X + ) has an electron depleted p-orbital that can interact simultaneously with two Lewis bases, forming a linear three-center, four-electron (3c4e) halogen bond.…”

Solid‐Phase Radical Polymerization of Halogen‐Bond‐Based Crystals and Applications to Pre‐Shaped Polymer Materials

“…Generally, free‐radical SPP would not meet this condition in a strict sense.) Halogen bonding (R−X⋅⋅⋅Y) is a noncovalent bonding between an electron‐accepting halogen (X) and an electron‐donating group (Y) . Halogen bonding is a directional 180° interaction and the strength increases in the order of R−F ≪ R−Cl < R−Br < R−I.…”