scholarly journals "ANTI-HALOGEN" BONDS AS A FACTOR DETERMINING THE TETRAHEDRAL STRUCTURE OF COPPER IN ITS COMPLEXES WITH (5Z, 5'Z)-2,2'- (ETHANE-1,2-DIYLDISULFANYLDIYL)BIS(5-(2-PYRIDYLMETHYLENE)-3-ALLYL-3,5-DIHYDRO- 4H-IMIDAZOLE-4-ONE)

2021 ◽  
Vol 2 (74) ◽  
pp. 38-41
Author(s):  
A. Al-Khazraji ◽  
I. Dudkin ◽  
E. Ofitserov ◽  
A. Finko ◽  
E. Beloglazkina
Keyword(s):  
Electron Density ◽  
Copper Atom ◽  
Halogen Bond ◽  
Halogen Bonds ◽  
Tetrahedral Structure ◽  
Angle Of Rotation

Analysis of the valence angles of the Si and carbon atoms of the C-S bond in the obtained complexes of CiVg2 c (5Z, 5'Z)-2,2’-(ethane-1,2-diyldisulfanyldiyl)bis(5-(2-pyridylmethylene)-3-allyl-3,5-dihydro-4Нimidazole-4-one) unambiguously indicates the determinant effect of the non-valent interactions of the electron density centroids of the NEP of bromine atoms and sulfur atoms, leading to a change in the plane structure of Cu(II) towards tetrahedral with a likely change in the magnetochemical properties of the copper atom, and the angle of rotation of the planes is almost 900. This interaction is the opposite of what is commonly called a halogen bond. In this case, it is an "anti-halogen" bond.

scholarly journals The many flavours of halogen bonds – message from experimental electron density and Raman spectroscopy

2019 ◽  
Vol 75 (9) ◽  
pp. 1190-1201 ◽  
Author(s):  
Ruimin Wang ◽  
Janine George ◽  
Shannon Kimberly Potts ◽  
Marius Kremer ◽  
Richard Dronskowski ◽  
...  
Keyword(s):  
Critical Point ◽  
Electron Density ◽  
Halogen Bond ◽  
Bond Distance ◽  
Bond Critical Point ◽  
Halogen Bonds ◽  
Derived Properties ◽  
The Many ◽  
A Minor ◽  
Experimental Electron Density

Experimental electron-density studies based on high-resolution diffraction experiments allow halogen bonds between heavy halogens to be classified. The topological properties of the electron density in Cl...Cl contacts vary smoothly as a function of the interaction distance. The situation is less straightforward for halogen bonds between iodine and small electronegative nucleophiles, such as nitrogen or oxygen, where the electron density in the bond critical point does not simply increase for shorter distances. The number of successful charge–density studies involving iodine is small, but at least individual examples for three cases have been observed. (a) Very short halogen bonds between electron-rich nucleophiles and heavy halogen atoms resemble three-centre–four-electron bonds, with a rather symmetric heavy halogen and without an appreciable σ hole. (b) For a narrow intermediate range of halogen bonds, the asymmetric electronic situation for the heavy halogen with a pronounced σ hole leads to rather low electron density in the (3,−1) critical point of the halogen bond; the properties of this bond critical point cannot fully describe the nature of the associated interaction. (c) For longer and presumably weaker contacts, the electron density in the halogen bond critical point is only to a minor extent reduced by the presence of the σ hole and hence may be higher than in the aforementioned case. In addition to the electron density and its derived properties, the halogen–carbon bond distance opposite to the σ hole and the Raman frequency for the associated vibration emerge as alternative criteria to gauge the halogen-bond strength. We find exceptionally long C—I distances for tetrafluorodiiodobenzene molecules in cocrystals with short halogen bonds and a significant red shift for their Raman vibrations.

scholarly journals Strength of the [Z–I···Hal]− and [Z–Hal···I]− Halogen Bonds: Electron Density Properties and Halogen Bond Length as Estimators of Interaction Energy

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2083
Author(s):  
Maxim L. Kuznetsov
Keyword(s):  
Bond Length ◽  
Interaction Energy ◽  
Electron Density ◽  
Halogen Bond ◽  
Bond Critical Point ◽  
Halogen Bonds ◽  
Curvature Potential ◽  
Non Covalent Interactions ◽  
Covalent Interactions

Bond energy is the main characteristic of chemical bonds in general and of non-covalent interactions in particular. Simple methods of express estimates of the interaction energy, Eint, using relationships between Eint and a property which is easily accessible from experiment is of great importance for the characterization of non-covalent interactions. In this work, practically important relationships between Eint and electron density, its Laplacian, curvature, potential, kinetic, and total energy densities at the bond critical point as well as bond length were derived for the structures of the [Z–I···Hal]– and [Z–Hal···I]– types bearing halogen bonds and involving iodine as interacting atom(s) (totally 412 structures). The mean absolute deviations for the correlations found were 2.06–4.76 kcal/mol.

Intermolecular binding preferences of haloethynyl halogen-bond donors as a function of molecular electrostatic potentials in a family of N-(pyridin-2-yl)amides

2021 ◽  
Author(s):  
Amila M. Abeysekera ◽  
Boris B. Averkiev ◽  
Pierre Le Magueres ◽  
Christer B. Aakeröy
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Halogen Bond ◽  
Electrostatic Potentials ◽  
Halogen Bonds ◽  
Molecular Electrostatic Potentials

The roles played by halogen bonds and hydrogen bonds in the crystal structures of N-(pyridin-2-yl)amides were evaluated and rationalised in the context of calculated molecular electrostatic potentials.

scholarly journals Using beryllium bonds to change halogen bonds from traditional to chlorine-shared to ion-pair bonds

2015 ◽  
Vol 17 (3) ◽  
pp. 2259-2267 ◽  
Author(s):  
Ibon Alkorta ◽  
José Elguero ◽  
Otilia Mó ◽  
Manuel Yáñez ◽  
Janet E. Del Bene
Keyword(s):  
Halogen Bond ◽  
Ion Pair ◽  
Ternary Complexes ◽  
Halogen Bonds ◽  
Bond Type ◽  
Cooperative Effects ◽  
Pair Bonds

Dramatic synergistic cooperative effects between Be⋯F beryllium bonds and Cl⋯N halogen bonds in XYBe:FCl:N-base ternary complexes lead to changes in the halogen-bond type from traditional to chlorine-shared to ion-pair bonds.

Cyclic networks of halogen-bonding interactions in molecular self-assemblies: a theoretical N—X...NversusC—X...N investigation

2017 ◽  
Vol 73 (2) ◽  
pp. 179-187
Author(s):  
Ruben D. Parra ◽  
Álvaro Castillo
Keyword(s):  
Electron Density ◽  
Self Assembly ◽  
Metal Ion ◽  
Halogen Atom ◽  
Halogen Bond ◽  
Halogen Bonding ◽  
Nbo Analysis ◽  
Binding Energies ◽  
Cyclic Network ◽  
Ability To Drive

The geometries and energetics of molecular self-assembly structures that contain a sequential network of cyclic halogen-bonding interactions are investigated theoretically. The strength of the halogen-bonding interactions is assessed by examining binding energies, electron charge transfer (NBO analysis) and electron density at halogen-bond critical points (AIM theory). Specifically, structural motifs having intramolecular N—X...N (X= Cl, Br, or I) interactions and the ability to drive molecular self-assemblyviathe same type of interactions are used to construct larger self-assemblies of up to three unit motifs. N—X...N halogen-bond cooperativity as a function of the self-assembly size, and the nature of the halogen atom is also examined. The cyclic network of the halogen-bonding interactions provides a suitable cavity rich in electron density (from the halogen atom lone pairs not involved in the halogen bonds) that can potentially bind an electron-deficient species such as a metal ion. This possibility is explored by examining the ability of the N—X...N network to bind Na+. Likewise, molecular self-assembly structures driven by the weaker C—X...N halogen-bonding interactions are investigated and the results compared with those of their N—X...N counterparts.

scholarly journals Relationships between Interaction Energy and Electron Density Properties for Homo Halogen Bonds of the [(A)nY–X···X–Z(B)m] Type (X = Cl, Br, I)

Molecules ◽  
2019 ◽  
Vol 24 (15) ◽  
pp. 2733 ◽  
Author(s):  
Maxim L. Kuznetsov
Keyword(s):  
Kinetic Energy ◽  
Interaction Energy ◽  
Electron Density ◽  
Bond Critical Point ◽  
Kinetic Energy Density ◽  
Large Set ◽  
Halogen Bonds ◽  
Absolute Deviation ◽  
The Individual ◽  
Best Estimator

Relationships between interaction energy (Eint) and electron density properties at the X···X bond critical point or the d(X···X) distance were established for the large set of structures [(A)nY–X···X–Z(B)m] bearing the halogen bonds Cl···Cl, Br···Br, and I···I (640 structures in total). The best estimator of Eint is the kinetic energy density (Gb), which reasonably approximates the whole set of the structures as −Eint = 0.128Gb2 − 0.82Gb + 1.66 (R2 = 0.91, mean absolute deviation 0.39 kcal/mol) and demonstrates low dispersion. The potential and kinetic energy densities, electron density, and the d(X···X) distance behave similarly as estimators of Eint for the individual series Cl···Cl, Br···Br, and I···I. A number of the Eint(property) correlations are recommended for the practical application in the express estimates of the strength of the homo-halogen bonds.

scholarly journals Halogen-Bonded Guanine Base Pairs, Quartets and Ribbons

2020 ◽  
Vol 21 (18) ◽  
pp. 6571
Author(s):  
Nicholas J. Thornton ◽  
Tanja van Mourik
Keyword(s):  
Base Pair ◽  
Halogen Bond ◽  
Halogen Bonding ◽  
Dna Bases ◽  
Halogen Bonds ◽  
Base Pairs ◽  
Rich Diversity ◽  
Different Types ◽  
Guanine Base ◽  
The Stability

Halogen bonding is studied in different structures consisting of halogenated guanine DNA bases, including the Hoogsteen guanine–guanine base pair, two different types of guanine ribbons (R-I and R-II) consisting of two or three monomers, and guanine quartets. In the halogenated base pairs (except the Cl-base pair, which has a very non-planar structure with no halogen bonds) and R-I ribbons (except the At trimer), the potential N-X•••O interaction is sacrificed to optimise the N-X•••N halogen bond. In the At trimer, the astatines originally bonded to N1 in the halogen bond donating guanines have moved to the adjacent O6 atom, enabling O-At•••N, N-At•••O, and N-At•••At halogen bonds. The brominated and chlorinated R-II trimers contain two N-X•••N and two N-X•••O halogen bonds, whereas in the iodinated and astatinated trimers, one of the N-X•••N halogen bonds is lost. The corresponding R-II dimers keep the same halogen bond patterns. The G-quartets display a rich diversity of symmetries and halogen bond patterns, including N-X•••N, N-X•••O, N-X•••X, O-X•••X, and O-X•••O halogen bonds (the latter two facilitated by the transfer of halogens from N1 to O6). In general, halogenation decreases the stability of the structures. However, the stability increases with the increasing atomic number of the halogen, and the At-doped R-I trimer and the three most stable At-doped quartets are more stable than their hydrogenated counterparts. Significant deviations from linearity are found for some of the halogen bonds (with halogen bond angles around 150°).

scholarly journals Noncovalent Bonds, Spectral and Thermal Properties of Substituted Thiazolo[2,3-b][1,3]thiazinium Triiodides

Crystals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 506 ◽  
Author(s):  
Irina Yushina ◽  
Natalya Tarasova ◽  
Dmitry Kim ◽  
Vladimir Sharutin ◽  
Ekaterina Bartashevich
Keyword(s):  
Electron Density ◽  
Noncovalent Interactions ◽  
Material Design ◽  
Spectroscopic Properties ◽  
Structural Features ◽  
Halogen Bonds ◽  
X Ray Diffraction ◽  
Raman Spectroscopic ◽  
Pairwise Interactions ◽  
Noncovalent Bonds

The interrelation between noncovalent bonds and physicochemical properties is in the spotlight due to the practical aspects in the field of crystalline material design. Such study requires a number of similar substances in order to reveal the effect of structural features on observed properties. For this reason, we analyzed a series of three substituted thiazolo[2,3-b][1,3]thiazinium triiodides synthesized by an iodocyclization reaction. They have been characterized with the use of X-ray diffraction, Raman spectroscopy, and thermal analysis. Various types of noncovalent interactions have been considered, and an S…I chalcogen bond type has been confirmed using the electronic criterion based on the calculated electron density and electrostatic potential. The involvement of triiodide anions in the I…I halogen and S…I chalcogen bonding is reflected in the Raman spectroscopic properties of the I–I bonds: identical bond lengths demonstrate different wave numbers of symmetric triiodide vibration and different values of electron density at bond critical points. Chalcogen and halogen bonds formed by the terminal iodine atom of triiodide anion and numerous cation…cation pairwise interactions can serve as one of the reasons for increased thermal stability and retention of iodine in the melt under heating.

scholarly journals Halogen bonds of halonium ions

2020 ◽  
Vol 49 (9) ◽  
pp. 2688-2700 ◽  
Author(s):  
Lotta Turunen ◽  
Máté Erdélyi
Keyword(s):  
Organic Chemistry ◽  
Halogen Bond ◽  
Halogen Bonds ◽  
Synthetic Organic Chemistry

Halonium ions are particularly strong halogen bond donors, and are accordingly valuable tools for a variety of fields, such as supramolecular and synthetic organic chemistry.

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