Halogen bond

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In chemistry, a halogen bond (XB or HaB [1] ) 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. [2] Like a hydrogen bond, the result is not a formal chemical bond, but rather a strong electrostatic attraction. [3] [4] Mathematically, the interaction can be decomposed in two terms: one describing an electrostatic, orbital-mixing charge-transfer and another describing electron-cloud dispersion. Halogen bonds find application in supramolecular chemistry; [3] [4] [5] drug design and biochemistry; [6] [7] crystal engineering [7] and liquid crystals; [3] and organic catalysis. [7]

Contents

Definition

Halogen bond in complex between iodine monochloride and trimethylamine. IodoChlorineAmine.jpg
Halogen bond in complex between iodine monochloride and trimethylamine.

Halogen bonds occur when a halogen atom is electrostatically attracted to a partial negative charge. Necessarily, the atom must be covalently bonded in an antipodal σ-bond; the electron concentration associated with that bond leaves a positively charged "hole" on the other side. [8] Although all halogens can theoretically participate in halogen bonds, the σ-hole shrinks if the electron cloud in question polarizes poorly or the halogen is so electronegative as to polarize the associated σ-bond. [3] [9] Consequently halogen-bond propensity follows the trend [10] [Note 1] F < Cl < Br < I.

There is no clear distinction between halogen bonds and expanded octet partial bonds; what is superficially a halogen bond may well turn out to be a full bond in an unexpectedly relevant resonance structure. [11] [12] [13] [14]

Donor characteristics

A halogen bond is almost collinear with the halogen atom's other, conventional bond, but the geometry of the electron-charge donor may be much more complex.

Anions are usually better halogen-bond acceptors than neutral species: the more dissociated an ion pair is, the stronger the halogen bond formed with the anion. [17]

Comparison to other bond-like forces

A parallel relationship can easily be drawn between halogen bonding and hydrogen bonding. Both interactions revolve around an electron donor/electron acceptor relationship, between a halogen-like atom and an electron-dense one. But halogen bonding is both much stronger and more sensitive to direction than hydrogen bonding. A typical hydrogen bond has energy of formation 20 kJ/mol; known halogen bond energies range from 10–200 kJ/mol. [16]

The σ-hole concept readily extends to pnictogen, chalcogen and aerogen bonds, corresponding to atoms of Groups 15, 16 and 18 (respectively). [18]

History

Chains in the 1:1 adduct of 1,4-dioxane and bromine, the first crystallographic evidence of halogen bonding. Bromine-dioxane.svg
Chains in the 1:1 adduct of 1,4-dioxane and bromine, the first crystallographic evidence of halogen bonding.

In 1814, Jean-Jacques Colin discovered (to his surprise) that a mixture of dry gaseous ammonia and iodine formed a shiny, metallic-appearing liquid. Frederick Guthrie established the precise composition of the resulting I2···NH3 complex fifty years later, but the physical processes underlying the molecular interaction remained mysterious until the development of Robert S. Mulliken's theory of inner-sphere and outer-sphere interactions. [19] In Mulliken's categorization, the intermolecular interactions associated with small partial charges affect only the "inner sphere" of an atom's electron distribution; the electron redistribution associated with Lewis adducts affects the "outer sphere" instead. [20]

Then, in 1954, Odd Hassel fruitfully applied the distinction to rationalize the X-ray diffraction patterns associated with a mixture of 1,4-dioxane and bromine. [21] The patterns suggested that only 2.71 Å separated the dioxane oxygen atoms and bromine atoms, much closer than the sum (3.35 Å) of the atoms' van der Waals radii; and that the angle between the O−Br and Br−Br bond was about 180°. From these facts, Hassel concluded that halogen atoms are directly linked to electron pair donors in a direction with a bond direction that coincides with the axes of the orbitals of the lone pairs in the electron pair donor molecule. [8] For this work, Hassel was awarded the 1969 Nobel Prize in Chemistry. [22]

Dumas and coworkers first coined the term "halogen bond" in 1978, during their investigations into complexes of CCl4, CBr4, SiCl4, and SiBr4 with tetrahydrofuran, tetrahydropyran, pyridine, anisole, and di-n-butyl ether in organic solvents. [23]

However, it was not until the mid-1990s, that the nature and applications of the halogen bond began to be intensively studied. Through systematic and extensive microwave spectroscopy of gas-phase halogen bond adducts, Legon and coworkers drew attention to the similarities between halogen-bonding and better-known hydrogen-bonding interactions. [24]

In 2007, computational calculations by Politzer and Murray showed that an anisotropic electron density distribution around the halogen nucleus — the "σ-hole" [9] — underlay the high directionality of the halogen bond. [25] This hole was then experimentally observed using Kelvin probe force microscopy. [26] [27]

In 2020, Kellett et al. showed that halogen bonds also have a π-covalent character similar to metal coordination bonds. [28] In August 2023 the "π-hole" was too experimentally observed [29] [30]

Applications

Crystal engineering

Br***O halogen bonds observed in the 3D crystal structure of certain silsesquioxanes. Silsesquixane halogen bond.tif
Br···O halogen bonds observed in the 3D crystal structure of certain silsesquioxanes.

The strength and directionality of halogen bonds are a key tool in the discipline of crystal engineering, which attempts to shape crystal structures through close control of intermolecular interactions. [32] Halogen bonds can stabilize copolymers [33] [34] or induce mesomorphism in otherwise isotropic liquids. [35] Indeed, halogen bond-induced liquid crystalline phases are known in both alkoxystilbazoles [35] and silsesquioxanes (pictured). [31] Alternatively, the steric sensitivity of halogen bonds can cause bulky molecules to crystallize into porous structures; in one notable case, halogen bonds between iodine and aromatic π-orbitals caused molecules to crystallize into a pattern that was nearly 40% void. [36]

Controlled polymerization

Conjugated polymers offer the tantalizing possibility of organic molecules with a manipulable electronic band structure, but current methods for production have an uncontrolled topology. Sun, Lauher, and Goroff discovered that certain amides ensure a linear polymerization of poly(diiododiacetylene). The underlying mechanism is a self-organization of the amides via hydrogen bonds that then transfers to the diiododiacetylene monomers via halogen bonds. Although pure diiododiacetylene crystals do not polymerize spontaneously, the halogen-bond induced organization is sufficiently strong that the cocrystals do spontaneously polymerize. [37]

Biological macromolecules

IDD 594 binding to human aldose reductase: a short Br-O halogen bond contributes to inhibitor potency. IDD.jpg
IDD 594 binding to human aldose reductase: a short Br−O halogen bond contributes to inhibitor potency.

Most biological macromolecules contain few or no halogen atoms. But when molecules do contain halogens, halogen bonds are often essential to understanding molecular conformation. Computational studies suggest that known halogenated nucleobases form halogen bonds with oxygen, nitrogen, or sulfur in vitro. Interestingly, oxygen atoms typically do not attract halogens with their lone pairs, but rather the π electrons in the carbonyl or amide group. [6]

Halogen bonding can be significant in drug design as well. For example, inhibitor IDD 594 binds to human aldose reductase through a bromine halogen bond, as shown in the figure. The molecules fail to bind to each other if similar aldehyde reductase replaces the enzyme, or chlorine replaces the drug halogen, because the variant geometries inhibit the halogen bond. [38]

Notes

  1. ↑ Although hydrogen is sometimes considered a halogen, convention excludes hydrogen bonds from the category of halogen bonds. For a complete analysis, see § Comparison to other bond-like forces.

Related Research Articles

<span class="mw-page-title-main">Hydrogen bond</span> Intermolecular attraction between a hydrogen-donor pair and an acceptor

In chemistry, a hydrogen bond is primarily an electrostatic force of attraction between a hydrogen (H) atom which is covalently bonded to a more electronegative "donor" atom or group (Dn), and another electronegative atom bearing a lone pair of electrons—the hydrogen bond acceptor (Ac). Such an interacting system is generally denoted Dn−H···Ac, where the solid line denotes a polar covalent bond, and the dotted or dashed line indicates the hydrogen bond. The most frequent donor and acceptor atoms are the period 2 elements nitrogen (N), oxygen (O), and fluorine (F).

An intermolecular force is the force that mediates interaction between molecules, including the electromagnetic forces of attraction or repulsion which act between atoms and other types of neighbouring particles, e.g. atoms or ions. Intermolecular forces are weak relative to intramolecular forces – the forces which hold a molecule together. For example, the covalent bond, involving sharing electron pairs between atoms, is much stronger than the forces present between neighboring molecules. Both sets of forces are essential parts of force fields frequently used in molecular mechanics.

<span class="mw-page-title-main">Catenation</span> Bonding of atoms of the same element into chains or rings

In chemistry, catenation is the bonding of atoms of the same element into a series, called a chain. A chain or a ring shape may be open if its ends are not bonded to each other, or closed if they are bonded in a ring. The words to catenate and catenation reflect the Latin root catena, "chain".

Supramolecular chemistry refers to the branch of chemistry concerning chemical systems composed of a discrete number of molecules. The strength of the forces responsible for spatial organization of the system range from weak intermolecular forces, electrostatic charge, or hydrogen bonding to strong covalent bonding, provided that the electronic coupling strength remains small relative to the energy parameters of the component. While traditional chemistry concentrates on the covalent bond, supramolecular chemistry examines the weaker and reversible non-covalent interactions between molecules. These forces include hydrogen bonding, metal coordination, hydrophobic forces, van der Waals forces, pi–pi interactions and electrostatic effects.

In chemistry, a hypervalent molecule is a molecule that contains one or more main group elements apparently bearing more than eight electrons in their valence shells. Phosphorus pentachloride, sulfur hexafluoride, chlorine trifluoride, the chlorite ion in chlorous acid and the triiodide ion are examples of hypervalent molecules.

<span class="mw-page-title-main">Charge-transfer complex</span> Association of molecules in which a fraction of electronic charge is transferred between them

In chemistry, charge-transfer (CT) complex, or electron donor-acceptor complex, describes a type of supramolecular assembly of two or more molecules or ions. The assembly consists of two molecules that self-attract through electrostatic forces, i.e., one has at least partial negative charge and the partner has partial positive charge, referred to respectively as the electron acceptor and electron donor. In some cases, the degree of charge transfer is "complete", such that the CT complex can be classified as a salt. In other cases, the charge-transfer association is weak, and the interaction can be disrupted easily by polar solvents.

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<span class="mw-page-title-main">Crystal engineering</span> Designing solid structures with tailored properties

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<span class="mw-page-title-main">Molecular solid</span> Solid consisting of discrete molecules

A molecular solid is a solid consisting of discrete molecules. The cohesive forces that bind the molecules together are van der Waals forces, dipole–dipole interactions, quadrupole interactions, π–π interactions, hydrogen bonding, halogen bonding, London dispersion forces, and in some molecular solids, coulombic interactions. Van der Waals, dipole interactions, quadrupole interactions, π–π interactions, hydrogen bonding, and halogen bonding are typically much weaker than the forces holding together other solids: metallic, ionic, and network solids. Intermolecular interactions typically do not involve delocalized electrons, unlike metallic and certain covalent bonds. Exceptions are charge-transfer complexes such as the tetrathiafulvane-tetracyanoquinodimethane (TTF-TCNQ), a radical ion salt. These differences in the strength of force and electronic characteristics from other types of solids give rise to the unique mechanical, electronic, and thermal properties of molecular solids.

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<span class="mw-page-title-main">Carbon–fluorine bond</span> Covalent bond between carbon and fluorine atoms

The carbon–fluorine bond is a polar covalent bond between carbon and fluorine that is a component of all organofluorine compounds. It is one of the strongest single bonds in chemistry, and relatively short, due to its partial ionic character. The bond also strengthens and shortens as more fluorines are added to the same carbon on a chemical compound. As such, fluoroalkanes like tetrafluoromethane are some of the most unreactive organic compounds.

Physical organic chemistry, a term coined by Louis Hammett in 1940, refers to a discipline of organic chemistry that focuses on the relationship between chemical structures and reactivity, in particular, applying experimental tools of physical chemistry to the study of organic molecules. Specific focal points of study include the rates of organic reactions, the relative chemical stabilities of the starting materials, reactive intermediates, transition states, and products of chemical reactions, and non-covalent aspects of solvation and molecular interactions that influence chemical reactivity. Such studies provide theoretical and practical frameworks to understand how changes in structure in solution or solid-state contexts impact reaction mechanism and rate for each organic reaction of interest.

Unlike its lighter congeners, the halogen iodine forms a number of stable organic compounds, in which iodine exhibits higher formal oxidation states than -1 or coordination number exceeding 1. These are the hypervalent organoiodines, often called iodanes after the IUPAC rule used to name them.

Giuseppe Resnati is an Italian chemist with interests in supramolecular chemistry and fluorine chemistry. He has a particular focus on self-assembly processes driven by halogen bonds, chalcogen bonds, and pnictogen bonds. His results on the attractive non-covalent interactions wherein atoms act as electrophiles thanks to the anisotropic distribution of the electron density typical for bonded atoms, prompted a systematic rationalization and categorization of many different weak bonds formed by many elements of the p- and d-blocks of the periodic table.

Pierangelo Metrangolo is an Italian chemist with interests in supramolecular chemistry and functional materials. He also has an interest in crystal engineering, in particular by using the halogen bond. He is Vice-President and President-Elect of the Physical and Biophysical Chemistry Division of IUPAC.

In chemistry, a chalcogen bond (ChB) is an attractive interaction in the family of σ-hole interactions, along with halogen bonds. Electrostatic, charge-transfer (CT) and dispersion terms have been identified as contributing to this type of interaction. In terms of CT contribution, this family of attractive interactions has been modeled as an electron donor interacting with the σ* orbital of a C-X bond of the bond donor. In terms of electrostatic interactions, the molecular electrostatic potential (MEP) maps is often invoked to visualize the electron density of the donor and an electrophilic region on the acceptor, where the potential is depleted, referred to as a σ-hole. ChBs, much like hydrogen and halogen bonds, have been invoked in various non-covalent interactions, such as protein folding, crystal engineering, self-assembly, catalysis, transport, sensing, templation, and drug design.

<span class="mw-page-title-main">Diiodoacetylene</span> Chemical compound

Diiodoacetylene is the organoiodine compound with the formula C2I2. It is a white, volatile solid that dissolves in organic solvents. It is prepared by iodination of trimethylsilylacetylene. Although samples explode above 80 °C, diiodoacetylene is the most readily handled of the dihaloacetylenes. Dichloroacetylene, for example, is more volatile and more explosive. As confirmed by X-ray crystallography, diiodoacetylene is linear. It is however a shock, heat and friction sensitive compound. Like other haloalkynes, diiodoacetylene is a strong halogen bond donor.

Dispersion stabilized molecules are molecules where the London dispersion force (LDF), a non-covalent attractive force between atoms and molecules, plays a significant role in promoting the molecule's stability. Distinct from steric hindrance, dispersion stabilization has only recently been considered in depth by organic and inorganic chemists after earlier gaining prominence in protein science and supramolecular chemistry. Although usually weaker than covalent bonding and other forms of non-covalent interactions like hydrogen bonding, dispersion forces are known to be a significant if not dominating stabilizing force in certain organic, inorganic, and main group molecules, stabilizing otherwise reactive moieties and exotic bonding.

In chemistry, sigma hole interactions are a family of intermolecular forces that can occur between several classes of molecules and arise from an energetically stabilizing interaction between a positively-charged site, termed a sigma hole, and a negatively-charged site, typically a lone pair, on different atoms that are not covalently bonded to each other. These interactions are usually rationalized primarily via dispersion, electrostatics, and electron delocalization and are characterized by a strong directional preference that allows control over supramolecular chemistry.

In chemistry, a pnictogen bond (PnB) is a non-covalent interaction, occurring where there is a net attractive force between an electrophilic region on a 'donor' pnictogen atom (Pn) in a molecule, and a nucleophilic region on an 'acceptor' atom, which may be in the same or another molecule. Closely related to halogen and chalcogen bonding, pnictogen bonds are a form of non-covalent interaction which can be considered in terms of charge-transfer and electrostatic interactions.

References

  1. ↑ Varadwaj, Pradeep R.; Varadwaj, Arpita; Marques, Helder M.; Yamashita, Koichi (2024-07-03). "Definition of the Halogen Bond (IUPAC Recommendations 2013): A Revisit". Crystal Growth & Design. 24 (13): 5494–5525. doi:10.1021/acs.cgd.4c00228. ISSN   1528-7483.
  2. ↑ Desiraju GR, Ho PS, Kloo L, Legon AC, Marquardt R, Metrangolo P, et al. (2013). "Definition of the Halogen Bond (IUPAC Recommendations 2013)". Pure Appl. Chem. 85 (8): 1711–1713. doi: 10.1351/pac-rec-12-05-10 .
  3. 1 2 3 4 Metrangolo P, Neukirch H, Pilati T, Resnati G (May 2005). "Halogen bonding based recognition processes: a world parallel to hydrogen bonding". Accounts of Chemical Research. 38 (5): 386–395. doi:10.1021/ar0400995. PMID   15895976.
  4. 1 2 Gilday LC, Robinson SW, Barendt TA, Langton MJ, Mullaney BR, Beer PD (August 2015). "Halogen Bonding in Supramolecular Chemistry". Chemical Reviews. 115 (15): 7118–7195. doi:10.1021/cr500674c. PMID   26165273.
  5. ↑ Metrangolo P, Resnati G (June 2001). "Halogen bonding: a paradigm in supramolecular chemistry". Chemistry. 7 (12): 2511–2519. doi:10.1002/1521-3765(20010618)7:12<2511::AID-CHEM25110>3.0.CO;2-T. PMID   11465442.
  6. 1 2 Auffinger P, Hays FA, Westhof E, Ho PS (November 2004). "Halogen bonds in biological molecules". Proceedings of the National Academy of Sciences of the United States of America. 101 (48): 16789–16794. Bibcode:2004PNAS..10116789A. doi: 10.1073/pnas.0407607101 . PMC   529416 . PMID   15557000.
  7. 1 2 3 Cavallo G, Metrangolo P, Milani R, Pilati T, Priimagi A, Resnati G, Terraneo G (February 2016). "The Halogen Bond". Chemical Reviews. 116 (4): 2478–2601. doi:10.1021/acs.chemrev.5b00484. PMC   4768247 . PMID   26812185.
  8. 1 2 Hassel O (October 1970). "Structural aspects of interatomic charge-transfer bonding". Science. 170 (3957): 497–502. Bibcode:1970Sci...170..497H. doi:10.1126/science.170.3957.497. PMID   17799698.
  9. 1 2 Clark T, Hennemann M, Murray JS, Politzer P (February 2007). "Halogen bonding: the sigma-hole. Proceedings of "Modeling interactions in biomolecules II", Prague, September 5th-9th, 2005". Journal of Molecular Modeling. 13 (2): 291–296. doi:10.1007/s00894-006-0130-2. PMID   16927107. S2CID   93970509.
  10. ↑ Politzer P, Lane P, Concha MC, Ma Y, Murray JS (February 2007). "An overview of halogen bonding". Journal of Molecular Modeling. 13 (2): 305–311. doi:10.1007/s00894-006-0154-7. PMID   17013631. S2CID   39255577.
  11. ↑ Wolters LP, Bickelhaupt FM (April 2012). "Halogen Bonding versus Hydrogen Bonding: A Molecular Orbital Perspective". ChemistryOpen. 1 (2): 96–105. doi:10.1002/open.201100015. PMC   3922460 . PMID   24551497.
  12. ↑ Aragoni MC, Arca M, Demartin F, Devillanova FA, Garau A, Isaia F, et al. (July 2005). "DFT calculations, structural and spectroscopic studies on the products formed between IBr and N,N'-dimethylbenzoimidazole-2(3H)-thione and -2(3H)-selone". Dalton Transactions (13): 2252–2258. doi:10.1039/B503883A. PMID   15962045.
  13. ↑ Eskandari K, Lesani M (March 2015). "Does fluorine participate in halogen bonding?". Chemistry. 21 (12): 4739–4746. doi:10.1002/chem.201405054. PMID   25652256.
  14. ↑ Turunen L, Hansen JH, Erdélyi M (May 2021). "Halogen Bonding: An Odd Chemistry?". Chemical Record. 21 (5): 1252–1257. doi: 10.1002/tcr.202100060 . hdl: 10037/22989 . PMID   33939244. S2CID   233483539.
  15. ↑ Aragoni MC, Arca M, Devillanova FA, Hursthouse MB, Huth SL, Isaia F, et al. (2005-04-15). "Reactions of pyridyl donors with halogens and interhalogens: an X-ray diffraction and FT-Raman investigation". Journal of Organometallic Chemistry. III Euchem Conference on Nitrogen Ligands in Organometallic Chemistry and Homogeneous Catalysis. 690 (8): 1923–1934. doi:10.1016/j.jorganchem.2004.11.001. ISSN   0022-328X.
  16. 1 2 Metrangolo P, Meyer F, Pilati T, Resnati G, Terraneo G (2008-08-04). "Halogen bonding in supramolecular chemistry". Angewandte Chemie. 47 (33): 6114–6127. doi:10.1002/anie.200800128. PMID   18651626.
  17. ↑ Liantonio R, Metrangolo P, Pilati T, Resnati G (2003-05-01). "Fluorous Interpenetrated Layers in a Three-Component Crystal Matrix". Crystal Growth & Design. 3 (3): 355–361. doi:10.1021/cg0340244. ISSN   1528-7483.
  18. ↑ Bauzá A, Frontera A (June 2015). "Aerogen Bonding Interaction: A New Supramolecular Force?". Angewandte Chemie. 54 (25): 7340–7343. doi:10.1002/anie.201502571. PMID   25950423.
  19. ↑ Guthrie F (1863). "Xxviii.—On the Iodide of Iodammonium". J. Chem. Soc. 16: 239–244. doi:10.1039/js8631600239.
  20. ↑
    • Mulliken RS (1950). "Structures of Complexes Formed by Halogen Molecules with Aromatic and with Oxygenated Solvents I.". J. Am. Chem. Soc. 72 (1): 600. doi:10.1021/ja01157a151.
    • Mulliken RS (1952). "Molecular Compounds and their Spectra. II". J. Am. Chem. Soc. 74 (3): 811–824. doi:10.1021/ja01123a067.
    • Mulliken RS (1952). "Molecular Compounds and their Spectra. III. The Interaction of Electron Donors and Acceptors". J. Phys. Chem. 56 (7): 801–822. doi:10.1021/j150499a001.
  21. ↑ Hassel O, Hvoslef J (1954). "The Structure of Bromine 1,4-Dioxanate" (PDF). Acta Chem. Scand. 8: 873. doi: 10.3891/acta.chem.scand.08-0873 .
  22. ↑ Hassel O (1972). "Structural Aspects of Interatomic Charge-Transfer Bonding". In Nobel Lectures, Chemistry 1963-1970: 314–329.
  23. ↑ Dumas JM, Peurichard H, Gomel M (1978). "CX4...Base Interactions as Models of Weak Charge-transfer Interactions: Comparison with Strong Charge-transfer and Hydrogen-bond Interactions". J. Chem. Res.(S). 2: 54–57.
  24. ↑ Legon AC (September 1999). "Prereactive Complexes of Dihalogens XY with Lewis Bases B in the Gas Phase: A Systematic Case for the Halogen Analogue B···XY of the Hydrogen Bond B···HX". Angewandte Chemie. 38 (18): 2686–2714. doi:10.1002/(sici)1521-3773(19990917)38:18<2686::aid-anie2686>3.0.co;2-6. PMID   10508357.
  25. ↑ Politzer P, Murray JS, Clark T (July 2010). "Halogen bonding: an electrostatically-driven highly directional noncovalent interaction". Physical Chemistry Chemical Physics. 12 (28): 7748–7757. Bibcode:2010PCCP...12.7748P. doi:10.1039/c004189k. PMID   20571692.
  26. ↑ Mallada B, Gallardo A, Lamanec M, de la Torre B, Špirko V, Hobza P, Jelinek P (November 2021). "Real-space imaging of anisotropic charge of σ-hole by means of Kelvin probe force microscopy". Science. 374 (6569): 863–867. Bibcode:2021Sci...374..863M. doi:10.1126/science.abk1479. PMID   34762455. S2CID   244039573.
  27. ↑ Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences (IOCB Prague). "First observation of an inhomogeneous electron charge distribution on an atom". phys.org. Retrieved 2023-09-07.
  28. ↑ Kellett CW, Kennepohl P, Berlinguette CP (July 2020). "π covalency in the halogen bond". Nature Communications. 11 (1): 3310. Bibcode:2020NatCo..11.3310K. doi: 10.1038/s41467-020-17122-7 . PMC   7335087 . PMID   32620765.
  29. ↑ Mallada B, Ondráček M, Lamanec M, Gallardo A, Jiménez-Martín A, de la Torre B, et al. (August 2023). "Visualization of π-hole in molecules by means of Kelvin probe force microscopy". Nature Communications. 14 (1): 4954. Bibcode:2023NatCo..14.4954M. doi:10.1038/s41467-023-40593-3. PMC   10432393 . PMID   37587123.
  30. ↑ Institute of Organic Chemistry and Biochemistry of the CAS. "Scientists confirm decades-old theory of non-uniform distribution of electron density in aromatic molecules". phys.org. Retrieved 2023-09-07.
  31. 1 2 Janeta M, Szafert S (2017-10-01). "Synthesis, characterization and thermal properties of T8 type amido-POSS with p-halophenyl end-group". Journal of Organometallic Chemistry. 847: 173–183. doi:10.1016/j.jorganchem.2017.05.044. ISSN   0022-328X.
  32. ↑ Metrangolo P, Resnati G, Pilati T, Terraneo G, Biella S (2009). "Anion coordination and anion-templated assembly under halogen bonding control". CrystEngComm . 11 (7): 1187–1196. doi:10.1039/B821300C.
  33. ↑ Corradi E, Meille SV, Messina MT, Metrangolo P, Resnati G (May 2000). "Halogen Bonding versus Hydrogen Bonding in Driving Self-Assembly Processes Perfluorocarbon-hydrocarbon self-assembly, part IX. This work was supported by MURST (Cofinanziamento '99) and EU (COST-D12-0012)". Communications. Angewandte Chemie. 39 (10). Wiley-VCH: 1782–1786. doi:10.1002/(SICI)1521-3773(20000515)39:10<1782::AID-ANIE1782>3.0.CO;2-5. PMID   10934360.
  34. ↑ Amico V, Meille SV, Corradi E, Messina MT, Resnati G (August 1998). "Perfluorocarbon−Hydrocarbon Self-Assembling. 1D Infinite Chain Formation Driven by Nitrogen···Iodine Interactions". Journal of the American Chemical Society. 120 (32): 8261–8262. doi:10.1021/ja9810686. ISSN   0002-7863.
  35. 1 2 Nguyen HL, Horton PN, Hursthouse MB, Legon AC, Bruce DW (January 2004). "Halogen bonding: a new interaction for liquid crystal formation". Journal of the American Chemical Society. 126 (1): 16–17. doi:10.1021/ja036994l. PMID   14709037.
  36. ↑ Pigge FC, Vangala VR, Kapadia PP, Swenson DC, Rath NP (October 2008). "Hexagonal crystalline inclusion complexes of 4-iodophenoxy trimesoate". Chemical Communications. 38 (39): 4726–4728. doi:10.1039/b809592b. PMID   18830473. S2CID   40424594.
  37. ↑ Sun A, Lauher JW, Goroff NS (May 2006). "Preparation of poly(diiododiacetylene), an ordered conjugated polymer of carbon and iodine". Science. 312 (5776): 1030–1034. Bibcode:2006Sci...312.1030S. doi:10.1126/science.1124621. PMID   16709780. S2CID   36045120.
  38. 1 2 Howard EI, Sanishvili R, Cachau RE, Mitschler A, Chevrier B, Barth P, et al. (June 2004). "Ultrahigh resolution drug design I: details of interactions in human aldose reductase-inhibitor complex at 0.66 A". Proteins. 55 (4): 792–804. doi: 10.1002/prot.20015 . PMID   15146478. S2CID   38388856. The electrostatic interaction between the Br atom of the inhibitor and the OG of Thr 113 has an unusually short distance of 2.973(4) Å. The short contact between Br and Thr 113 OG explains the selectivity of IDD 594 towards AR, because in aldehyde reductase the Thr residue is replaced by Tyr....The IDD 594-Br/Thr 113-OG interaction also contributes to the potency of the inhibitor. Other halogens, such as chlorine, cannot engage in a similar interaction (due to its lower polarizability).

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