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

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.

2017 ◽  
Vol 203 ◽  
pp. 29-45 ◽  
Author(s):  
Janet E. Del Bene ◽  
Ibon Alkorta ◽  
José Elguero

Ab initio MP2/aug’-cc-pVTZ calculations have been carried out to determine the effect of the presence of one halogen bond on the nature of the other in ternary complexes H2XP:ClF:ClH and H2XP:ClF:ClF, for X = F, Cl, H, NC, and CN. The P⋯Cl bonds remain chlorine-shared halogen bonds in the ternary complexes H2XP:ClF:ClH, although the degree of chlorine sharing increases relative to the corresponding binary complexes. The F⋯Cl bonds in the ternary complexes remain traditional halogen bonds. The binding energies of the complexes H2XP:ClF:ClH increase relative to the corresponding binary complexes, and nonadditivities of binding energies are synergistic. In contrast, the presence of two halogen bonds in the ternary complexes H2XP:ClF:ClF has a dramatic effect on the nature of these bonds in the four most strongly bound complexes. In these, chlorine transfer occurs across the P⋯Cl halogen bond to produce complexes represented as (H2XP–Cl)+:−(F:ClF). In the ion-pair, the cation is also halogen bonded to the anion by a Cl⋯F− halogen bond, while the anion is stabilized by an −F⋯Cl halogen bond. The central ClF molecule no longer exists as a molecule. The binding energies of the ternary H2XP:ClF:ClF complexes are significantly greater than the binding energies of the H2XP:ClF:ClH complexes, and nonadditivities exhibit large synergistic effects. The Wiberg bond indexes for the complexes H2XP:ClF, H2XP:ClF:ClH, and H2XP:ClF:ClF, and the cations (H2XP–Cl)+ reflect the changes in the P–Cl and Cl–F bonds. Similarly, EOM-CCSD spin–spin coupling constants are also consistent with the changes in these same bonds. In particular, 1xJ(P–Cl) in H2XP:ClF complexes becomes 1J(P–Cl) in the ternary complexes with chlorine-transferred halogen bonds. A plot of these coupling constants shows a change in the curvature of the trendline as chlorine-shared halogen bonds in H2XP:ClF:ClH become chlorine-transferred halogen bonds in H2XP:ClF:ClF. 1xJ(F–Cl) coupling constants also reflect changes in the nature of F⋯Cl halogen bonds.


Author(s):  
Amila M. Abeysekera ◽  
Boris B. Averkiev ◽  
Pierre Le Magueres ◽  
Christer B. Aakeröy

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.


2021 ◽  
Vol 2 (74) ◽  
pp. 38-41
Author(s):  
A. Al-Khazraji ◽  
I. Dudkin ◽  
E. Ofitserov ◽  
A. Finko ◽  
E. Beloglazkina

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.


2020 ◽  
Vol 21 (18) ◽  
pp. 6571
Author(s):  
Nicholas J. Thornton ◽  
Tanja van Mourik

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°).


2020 ◽  
Vol 49 (9) ◽  
pp. 2688-2700 ◽  
Author(s):  
Lotta Turunen ◽  
Máté Erdélyi

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.


IUCrJ ◽  
2015 ◽  
Vol 2 (5) ◽  
pp. 498-510 ◽  
Author(s):  
Christer B. Aakeröy ◽  
Christine L. Spartz ◽  
Sean Dembowski ◽  
Savannah Dwyre ◽  
John Desper

As halogen bonds gain prevalence in supramolecular synthesis and materials chemistry, it has become necessary to examine more closely how such interactions compete with or complement hydrogen bonds whenever both are present within the same system. As hydrogen and halogen bonds have several fundamental features in common, it is often difficult to predict which will be the primary interaction in a supramolecular system, especially as they have comparable strength and geometric requirements. To address this challenge, a series of molecules containing both hydrogen- and halogen-bond donors were co-crystallized with various monotopic, ditopic symmetric and ditopic asymmetric acceptor molecules. The outcome of each reaction was examined using IR spectroscopy and, whenever possible, single-crystal X-ray diffraction. 24 crystal structures were obtained and subsequently analyzed, and the synthon preferences of the competing hydrogen- and halogen-bond donors were rationalized against a background of calculated molecular electrostatic potential values. It has been shown that readily accessible electrostatic potentials can offer useful practical guidelines for predicting the most likely primary synthons in these co-crystals as long as the potential differences are weighted appropriately.


2018 ◽  
Vol 42 (13) ◽  
pp. 10529-10538 ◽  
Author(s):  
Ferdinand Groenewald ◽  
Jan Dillen ◽  
Catharine Esterhuysen

A theoretical investigation shows that the Au(i) centre in a variety of complexes can behave as a halogen bond acceptor.


Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 530
Author(s):  
Juan Zurita ◽  
Vladimir Rodriguez ◽  
Cesar Zambrano ◽  
Jose Ramón Mora ◽  
Luis Rincón ◽  
...  

In the present work, a number of R–X⋯NH3 (X = Cl, Br, and I) halogen bonded systems were theoretical studied by means of DFT calculations performed at the ωB97XD/6-31+G(d,p) level of theory in order to get insights on the effect of the electron-donating or electron-withdrawing character of the different R substituent groups (R = halogen, methyl, partially fluorinated methyl, perfluoro-methyl, ethyl, vinyl, and acetyl) on the stability of the halogen bond. The results indicate that the relative stability of the halogen bond follows the Cl < Br < I trend considering the same R substituent whereas the more electron-withdrawing character of the R substituent the more stable the halogen bond. Refinement of the latter results, performed at the MP2/6-31+G(d,p) level showed that the DFT and the MP2 binding energies correlate remarkably well, suggesting that the Grimme’s type dispersion-corrected functional produces reasonable structural and energetic features of halogen bond systems. DFT results were also observed to agree with more refined calculations performed at the CCSD(T) level. In a further stage, a more thorough analysis of the R–Br⋯NH3 complexes was performed by means of a novel electron localization/delocalization tool, defined in terms of an Information Theory, IT, based quantity obtained from the conditional pair density. For the latter, our in-house developed C++/CUDA program, called KLD (acronym of Kullback–Leibler divergence), was employed. KLD results mapped onto the one-electron density plotted at a 0.04 a.u. isovalue, showed that (i) as expected, the localized electron depletion of the Br sigma-hole is largely affected by the electron-withdrawing character of the R substituent group and (ii) the R–X bond is significantly polarized due to the presence of the NH3 molecule in the complexes. The afore-mentioned constitutes a clear indication of the dominant character of electrostatics on the stabilization of halogen bonds in agreement with a number of studies reported in the main literature. Finally, the cooperative effects on the [Br—CN]n system (n = 1–8) was evaluated at the MP2/6-31+G(d,p) level, where it was observed that an increase of about ~14.2% on the complex stability is obtained when going from n = 2 to n = 8. The latter results were corroborated by the analysis of the changes on the Fermi-hole localization pattern on the halogen bond zones, which suggests an also important contribution of the electron correlation in the stabilization of these systems.


Crystals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 140 ◽  
Author(s):  
Yu Zhang ◽  
Jian-Ge Wang ◽  
Weizhou Wang

How many strong C−I⋯N halogen bonds can one 1,3,5-trifluoro-2,4,6-triiodobenzene molecule form in a crystal structure? To answer this question, we investigated in detail the noncovalent interactions between 1,3,5-trifluoro-2,4,6-triiodobenzene and a series of 1,10-phenanthroline derivatives by employing a combined theoretical and experimental method. The results of the quantum chemical calculations and crystallographic experiments clearly show that there is a structural competition between a C−I⋯N halogen bond and π⋯π stacking interaction. For example, when there are much stronger π⋯π stacking interactions between two 1,10-phenanthroline derivative molecules or between two 1,3,5-trifluoro-2,4,6-triiodobenzene molecules in the crystal structures, then one 1,3,5-trifluoro-2,4,6-triiodobenzene molecule forms only one C−I⋯N halogen bond with one 1,10-phenanthroline derivative molecule. Another example is when π⋯π stacking interactions in the crystal structures are not much stronger, one 1,3,5-trifluoro-2,4,6-triiodobenzene molecule can form two C−I⋯N halogen bonds with two 1,10-phenanthroline derivative molecules.


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