Theoretical Study on the Dual Behavior of XeO3and XeF4toward Aromatic Rings: Lone Pair-π versus Aerogen-π Interactions

ChemPhysChem ◽  
2015 ◽  
Vol 16 (17) ◽  
pp. 3625-3630 ◽  
Author(s):  
Antonio Bauzá ◽  
Antonio Frontera
Keyword(s):  
Theoretical Study ◽  
Lone Pair ◽  
Aromatic Rings ◽  
Π Interactions

scholarly journals Can lone pair-π and cation-π interactions coexist? A theoretical study

2011 ◽  
Vol 9 (1) ◽  
pp. 25-34 ◽  
Author(s):  
Carolina Estarellas ◽  
Antonio Frontera ◽  
David Quiñonero ◽  
Pere Deyà
Keyword(s):  
Interaction Potential ◽  
Theoretical Study ◽  
Noncovalent Interactions ◽  
Lone Pair ◽  
Geometric Features ◽  
Aromatic Rings ◽  
Partition Scheme ◽  
Π Interactions ◽  
Cooperativity Effects ◽  
Structural Database

AbstractThe interplay between two important noncovalent interactions involving different aromatic rings is studied by means of ab initio calculations (MP2/6-31++G**) computing the non-additivity energies. In this study we demonstrate the existence of cooperativity effects when cation-π and lone pair-π interactions coexist in the same system. These effects are studied theoretically using energetic and geometric features of the complexes. In addition we use Bader’s theory of atoms-in-molecules and Molecular Interaction Potential with polarization (MIPp) partition scheme to characterize the interactions. Experimental evidence for this combination of interactions has been obtained from the Cambridge Structural Database.

Energetic Effects between Halogen Bonds and Anion-π or Lone Pair-π Interactions: A Theoretical Study

2012 ◽  
Vol 116 (10) ◽  
pp. 2591-2597 ◽  
Author(s):  
Yunxiang Lu ◽  
Yingtao Liu ◽  
Haiying Li ◽  
Xiang Zhu ◽  
Honglai Liu ◽  
...  
Keyword(s):  
Theoretical Study ◽  
Lone Pair ◽  
Halogen Bonds ◽  
Π Interactions

scholarly journals The Affinity of Carboplatin to B-Vitamins and Nucleobases

2021 ◽  
Vol 22 (7) ◽  
pp. 3634
Author(s):  
Beata Szefler ◽  
Przemysław Czeleń ◽  
Przemysław Krawczyk
Keyword(s):  
Vitamin B6 ◽  
Pyridoxal Phosphate ◽  
Antitumor Agents ◽  
Lone Pair ◽  
Chemical Compounds ◽  
Free Energies ◽  
Aromatic Rings ◽  
Anti Cancer ◽  
Potential Impact ◽  
Reactive Molecule

Platinum compounds have found wide application in the treatment of various types of cancer and carboplatin is one of the main platinum-based drugs used as antitumor agents. The anticancer activity of carboplatin arises from interacting with DNA and inducing programmed cell death. However, such interactions may occur with other chemical compounds, such as vitamins containing aromatic rings with lone-pair orbitals, which reduces the anti-cancer effect of carboplatin. The most important aspect of the conducted research was related to the evaluation of carboplatin affinity to vitamins from the B group and the potential impact of such interactions on the reduction of therapeutic capabilities of carboplatin in anticancer therapy. Realized computations, including estimation of Gibbs Free Energies, allowed for the identification of the most reactive molecule, namely vitamin B6 (pyridoxal phosphate). In this case, the computational estimations indicating carboplatin reactivity were confirmed by spectrophotometric measurements.

Through-Space Transmission of 19F-13C Coupling Via an Intermediate Bond. An Experimental and Theoretical Study

1987 ◽  
Vol 40 (12) ◽  
pp. 1923 ◽  
Author(s):  
ID Rae ◽  
ID Rae ◽  
A Staffa ◽  
A Staffa ◽  
AC Diz ◽  
...  
Keyword(s):  
Theoretical Study ◽  
Lone Pair ◽  
Electron Excitation ◽  
Carbonyl Groups ◽  
Polarization Propagator ◽  
Close Proximity ◽  
Fermi Contact ◽  
Intramolecular Hydrogen ◽  
Intermediate Bond ◽  
Insight Into

In order to obtain a deeper insight into the title effect, several compounds with an F atom very close to a C-H of a nearby functional group were synthesized and the relevant couplings measured. The most conspicuous case was that of 8-fluoro-2-hydroxynaphthalene-1-carbaldehyde where a close proximity between the F and H atoms is the result of fluorine-oxygen repulsion and the formation of an intramolecular hydrogen bond between the hydroxyl and carbonyl groups. The experimental four-bond J(F,CHO) coupling is 26.2 Hz. A compound very similar to this one, but without the OH group, was chosen on which to perform a polarization propagator analysis of the through-space (TS) coupling pathways, at the RPA-INDO level. The expression for the TS coupling in terms of the projected polarization propagator and perturbators was numerically analysed. It is found that this coupling is completely dominated by a TS component of the Fermi contact (FC) term, the main features of which are: ( i ) It decays exponentially with the F-H distance; (ii) Its main contribution comes from an electron excitation involving the F lone-pair, the C-H bond of the CHO moiety and its corresponding antibonding orbital;(iii) The π-type lone-pair does not contribute to the TS coupling pathway of the FC term.

scholarly journals N′-(3-Hydroxybenzylidene)-4-methylbenzohydrazide

2012 ◽  
Vol 68 (6) ◽  
pp. o1816-o1816
Author(s):  
Ji-Lai Liu ◽  
Ming-Hui Sun ◽  
Jing-Jun Ma
Keyword(s):  
Hydrogen Bonds ◽  
Dihedral Angle ◽  
Title Compound ◽  
Crystal Packing ◽  
Aromatic Rings ◽  
Π Interactions ◽  
Compound C ◽  
Centroid Distance ◽  
Benzene Rings

The title compound, C15H14N2O2, was obtained from the reaction of 3-hydroxybenzaldhyde and 4-methylbenzohydrazide in methanol. In the molecule, the benzene rings form a dihedral angle of 2.9 (3)°. In the crystal, N—H...O and O—H...O hydrogen bonds link the molecules into layers parallel to (101). The crystal packing also exhibits π–π interactions between the aromatic rings [centroid–centroid distance = 3.686 (4) Å].

2-Pyridylcyanoxime-NiIIClusters with Unusual Topologies: Lone-Pair-π Interactions and Magnetic Properties

2014 ◽  
Vol 2014 (31) ◽  
pp. 5443-5450 ◽  
Author(s):  
Albert Escuer ◽  
Jordi Esteban ◽  
Júlia Mayans ◽  
Mercè Font-Bardia
Keyword(s):  
Magnetic Properties ◽  
Lone Pair ◽  
Π Interactions

scholarly journals Crystal structures of 2-methylpyridinium hydrogen 2,3-bis(4-methylbenzoyloxy)succinate and bis-[4-methylpyridinium hydrogen 2,3-bis(4-methylbenzoyloxy)succinate] pentahydrate

2017 ◽  
Vol 73 (10) ◽  
pp. 1483-1487
Author(s):  
P. Sivakumar ◽  
S. Israel ◽  
G. Chakkaravarthi
Keyword(s):  
Hydrogen Bonds ◽  
Pyridine Ring ◽  
Crystal Packing ◽  
Water Molecules ◽  
Two Dimensional ◽  
Asymmetric Unit ◽  
Aromatic Rings ◽  
Π Interactions ◽  
Dimensional Network ◽  
Anions And Cations

The title salt (I), C6H8N+·C20H17O8−, comprises a 2-methylpyridinium cation and a 2,3-bis(4-methylbenzoyloxy)succinate mono-anion while the salt (II), 2C6H8N+·2C20H17O8−·5H2O, consists of a pair of 4-methylpyridinium cations and 2,3-bis(4-methylbenzoyloxy)succinate mono-anions and five water molecules of solvation in the asymmetric unit. In (I), the dihedral angle between the aromatic rings of the anion is 40.41 (15)°, comparing with 43.0 (3) and 85.7 (2)° in the conformationally dissimilar anion molecules in (II). The pyridine ring of the cation in (I) is inclined at 23.64 (16) and 42.69 (17)° to the two benzene moieties of the anion. In (II), these comparative values are 4.7 (3), 43.5 (3)° and 43.5 (3), 73.1 (3)° for the two associated cation and anion pairs. The crystal packing of (I) is stabilized by inter-ionic N—H...O, O—H...O and C—H...O hydrogen bonds as well as weak C—H...π interactions, linking the ions into infinite chains along [100]. In the crystal packing of (II), the anions and cations are also linked by N—H...O and O—H...O hydrogen bonds involving also the water molecules, giving a two-dimensional network across (001). The crystal structure is also stabilized by weak C—H...O and C—H...π interactions.

scholarly journals Crystal structure of poly[[[μ4-5-(9H-carbazol-9-yl)isophthalato][μ3-5-(9H-carbazol-9-yl)isophthalato]bis(dimethylformamide)(methanol)dizinc] dimethylformamide monosolvate]

2015 ◽  
Vol 71 (8) ◽  
pp. m152-m153 ◽  
Author(s):  
Liubov M. Lifshits ◽  
Charles Campana ◽  
Jeremy K. Klosterman
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Title Compound ◽  
Solvent Molecule ◽  
Lone Pair ◽  
Π Interactions ◽  
Carboxylate Groups ◽  
Medium Strength ◽  
Secondary Building Units ◽  
Coordination Spheres

The structure of the polymeric title compound, {[Zn2(C20H11NO4)2(C3H7NO)2(CH3OH)]·C3H7NO}n, comprises carbazolylisophthalate moieties connecting dimetallic tetracarboxylate zinc secondary building units (SBUs) parallel to [100] and [010], leading to a layer-like arrangement parallel to (001). Each SBU consists of two Zn atoms in slightly distorted tetrahedral and octahedral coordination environments [Zn...Zn = 3.5953 (6) Å]. Three carboxylate groups bridge the two Zn atoms in a μ2-O:O′ mode, whereas the fourth coordinates through a single carboxylate O atom (μ1-O). The O atoms of two dimethylformamide (DMF) and one methanol molecule complete the Zn coordination spheres. The methanol ligand interacts with the noncoordinating DMF moleculeviaan O—H...O hydrogen bond of medium strength. Carbazoles between the layers interdigitate through weak C—H....π interactions to form a laminar solid stacked along [010]. Two kinds of C—H...π interactions are present, both with a distance of 2.64 Å, between the H atoms and the centroids, and a third C—H...π interaction, where the aromatic H atom is located above the carbazole N-atom lone pair (H...N = 2.89 Å). Several C—H...O interactions occur between the coordinating DMF molecule, the DMF solvent molecule, and ligating carboxylate O atoms.

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