scholarly journals Exploring Orthogonality between Halogen and Hydrogen Bonding Involving Benzene

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7126
Author(s):  
Alessandra Forni ◽  
Rosario Russo ◽  
Giacomo Rapeti ◽  
Stefano Pieraccini ◽  
Maurizio Sironi
Keyword(s):  
Hydrogen Bonding ◽  
Dft Calculations ◽  
Original Work ◽  
Electron System ◽  
Carbonyl Oxygen ◽  
Acceptor Group ◽  
Perpendicular Geometry

The concept of orthogonality between halogen and hydrogen bonding, brought out by Ho and coworkers some years ago, has become a widely accepted idea within the chemists’ community. While the original work was based on a common carbonyl oxygen as acceptor for both interactions, we explore here, by means of M06-2X, M11, ωB97X, and ωB97XD/aug-cc-PVTZ DFT calculations, the interdependence of halogen and hydrogen bonding with a shared π-electron system of benzene. The donor groups (specifically NCBr and H2O) were placed on either or the same side of the ring, according to a double T-shaped or a perpendicular geometry, respectively. The results demonstrate that the two interactions with benzene are not strictly independent on each other, therefore outlining that the orthogonality between halogen and hydrogen bonding, intended as energetical independence between the two interactions, should be carefully evaluated according to the specific acceptor group.

Sequential microhydration of cationic 5-hydroxyindole (5HI+): infrared photodissociation spectra of 5HI+–Wn clusters (W = H2O, n ≤ 4)

2018 ◽  
Vol 20 (5) ◽  
pp. 3092-3108 ◽  
Author(s):  
Johanna Klyne ◽  
Mitsuhiko Miyazaki ◽  
Masaaki Fujii ◽  
Otto Dopfer
Keyword(s):  
Hydrogen Bonding ◽  
Infrared Spectroscopy ◽  
Dft Calculations ◽  
Bonding Properties

The hydrogen-bonding properties of the acidic OH and NH groups of the 5-hydroxyindole cation are probed by infrared spectroscopy and DFT calculations of its microhydrated clusters.

Competition between coordination bonds and hydrogen bonding interactions in solvatomorphs of copper(II), cadmium(II) and cobalt(II) complexes with 2,2′-bipyridyl and acetate

2019 ◽  
Vol 234 (2) ◽  
pp. 119-128 ◽  
Author(s):  
José Antônio do Nascimento Neto ◽  
Cameron Capeletti da Silva ◽  
Leandro Ribeiro ◽  
Ana Karoline Silva Mendanha Valdo ◽  
Felipe Terra Martins
Keyword(s):  
Hydrogen Bonding ◽  
Dft Calculations ◽  
Organic Molecules ◽  
Energy Difference ◽  
Water Molecules ◽  
Coordination Numbers ◽  
Lattice Water ◽  
Hydrogen Bonding Interactions ◽  
Metal Organic ◽  
Coordination Bonds

Abstract The delicate balance among conformation, coordination bonds and hydrogen bonding has been probed in solvatomorphs of known metal-organic molecules synthesised from copper(II), cadmium(II) and cobalt(II) with acetate (OAc) and 2,2′-bipyridine (bipy). The Cu(OAc)2(bipy) complex, isolated as a pentahydrate, has the acetate ligands oriented to opposite sides of the coordination square plane. DFT calculations show the energy difference between this structure and a syn form amount to approximately 16 kJ/mol. The presence of lattice water enables the formation of O–H···O hydrogen bonds with the acetate ligands. Different coordination numbers and energies are found as a function of the number of water molecules co-crystallising in the Cd(OAc)2(bipy)(OH2)·3H2O and [Co(OAc)(bipy)2](OAc)·3H2O complexes.

Beziehungen zwischen Rotationsisomerie, Wasserstoffbrücken-Bindung und Substituenteneffekten der organischen Chemie / Relations between Rotational Isomerism, Hydrogen Bonding, and Substituent Effects in Organic Chemistry

1972 ◽  
Vol 27 (6) ◽  
pp. 663-674 ◽  
Author(s):  
Gotthard H. Krause ◽  
Herbert Hoyer
Keyword(s):  
Hydrogen Bonding ◽  
Substituent Effects ◽  
Intramolecular Hydrogen Bonding ◽  
Rotational Isomerism ◽  
Proton Acceptor ◽  
Single Bond ◽  
Free Enthalpy ◽  
Acceptor Group ◽  
Intramolecular Hydrogen ◽  
Derivatives Of

The change of free enthalpy involved in intramolecular hydrogen bonding is smaller if the proton acceptor group can rotate round a single bond, as compared to proton acceptor groups which are fixed in a position optimal for hydrogen bonding. Also, the free enthalpy change is altered when the rotation of the proton acceptor is sterically restricted. This is demonstrated by comparing the absorptions of carbonyl stretching vibrations in the infrared spectra of certain compounds showing rotational isomerism. In the present study derivatives of 5-hydroxy-2,2-dimethyl-6-carbomethoxychromanone- (4), 3-nitrosalicylaldehyde and 3-nitro-2-hydroxy-acetophenones substituted in the position 5 and 6 are examined.

Fluorescence characteristic and molecular interaction in the excited state of 1,2,3,4-tetrahydroquinoline

1984 ◽  
Vol 62 (7) ◽  
pp. 1369-1372 ◽  
Author(s):  
Kakali Chatterjee ◽  
Santanu Laha ◽  
Sankar Chakravorti ◽  
Tapan Ganguly ◽  
Sukhendu B. Banerjee
Keyword(s):  
Hydrogen Bonding ◽  
Excited State ◽  
Electron System ◽  
Reaction Scheme ◽  
Ternary Mixtures ◽  
Probable Case ◽  
Electronic Delocalization ◽  
Diffusion Controlled ◽  
Binary And Ternary Mixtures ◽  
Different Temperatures

Fluorescence spectra of 1,2,3,4-tetrahydroquinoline (THQ) in binary and ternary mixtures in nonpolar and hydrogen bonding solvents at different temperatures are investigated. A probable case of partial protonation of THQ at 300 K due to hydrogen bonding in the excited state with ethanol is reported. At 77 K, there is no significant hydrogen bonding interaction between these molecules. Interaction between the n-orbital of triethylamine (TEA) and the π-electron system of excited THQ results in the formation of a CT-type complex which causes slow quenching of the fluorescence of THQ at 300 K. This quenching is not observed at 77 K because restriction of molecular orientation at 77 K prevents the formation of such complex In pyridine, the fluorescence is strongly quenched both at room temperature and at 77 K. This has been attributed to π-electronic delocalization interaction between the fluorescer THQ and the nonfluorescing quencher pyridine. Possibility of conformational change is suggested. Rate constants associated with suitable reaction scheme for depletion of excited state are estimated. It is indicated that the quenching of fluorescence may be largely diffusion controlled.

Electrostatic Potential at Nuclei

2014 ◽  
pp. 87-122
Author(s):  
Sonia Ilieva ◽  
Boris Galabov
Keyword(s):  
Hydrogen Bonding ◽  
Kinetic Parameters ◽  
Organic Compounds ◽  
Electrostatic Potential ◽  
Original Work ◽  
Computational Approach ◽  
Reactivity Index ◽  
Quantum Mechanical ◽  
Mechanical Quantity ◽  
Substituent Constants

The chapter surveys mostly original work of the authors on the application of the electrostatic potential at nuclei (EPN) as a reactivity index in quantifying hydrogen bonding as well as different reactions of organic compounds. The EPN index was defined and introduced by E. B. Wilson (1962). However, it was first applied as a reactivity index much later in works from our laboratory (Bobadova-Parvanova & Galabov, 1998; Galabov & Bobadova-Parvanova, 1999; Dimitrova, Ilieva, & Galabov, 2002; Cheshmedzhieva, Ilieva, Hadjieva, Trayanova, & Galabov, 2009; Galabov, Cheshmedzhieva, Ilieva, & Hadjieva, 2004; Galabov, Ileiva, & Schaefer, 2006; Galabov, Nikolova, Wilke, Schaefer, & Allen, 2008; Galabov, Ilieva, Hadjieva, Atanasov, & Schaefer, 2008; Koleva, Galabov, Wu, Schaefer, & Schleyer, 2009). Numerous applications showed that the EPN index, an accurate quantum mechanical quantity, predicts with remarkable accuracy the energy shifts accompanying hydrogen bonding. The theoretically evaluated EPN descriptor correlates also excellently with experimental and theoretically evaluated kinetic parameters for a number of important organic reactions. Based on these findings an efficient computational approach for the evaluation of substituent constants was developed.

scholarly journals Intermolecular Non-Covalent Carbon-Bonding Interactions with Methyl Groups: A CSD, PDB and DFT Study

Molecules ◽  
2019 ◽  
Vol 24 (18) ◽  
pp. 3370 ◽  
Author(s):  
Tiddo J. Mooibroek
Keyword(s):  
Hydrogen Bonding ◽  
Solid State ◽  
Dft Calculations ◽  
Interaction Energy ◽  
Weak Interaction ◽  
Systematic Evaluation ◽  
Methyl Groups ◽  
Interaction Energies ◽  
Hydrogen Bonding Interactions ◽  
Carbon Bonding

A systematic evaluation of the CSD and the PDB in conjunction with DFT calculations reveal that non-covalent Carbon-bonding interactions with X–CH3 can be weakly directional in the solid state (P ≤ 1.5) when X = N or O. This is comparable to very weak CH hydrogen bonding interactions and is in line with the weak interaction energies calculated (≤ –1.5 kcal·mol−1) of typical charge neutral adducts such as [Me3N-CH3···OH2] (2a). The interaction energy is enhanced to ≤–5 kcal·mol−1 when X is more electron withdrawing such as in [O2N-CH3··O=Cdme] (20b) and to ≤18 kcal·mol−1 in cationic species like [Me3O+-CH3···OH2]+ (8a).

σ-Hole halogen bonding interactions in a mixed valence cobalt(iii/ii) complex and anti-electrostatic hydrogen bonding interaction in a cobalt(iii) complex: a theoretical insight

CrystEngComm ◽  
2018 ◽  
Vol 20 (45) ◽  
pp. 7281-7292 ◽  
Author(s):  
Kousik Ghosh ◽  
Klaus Harms ◽  
Antonio Bauzá ◽  
Antonio Frontera ◽  
Shouvik Chattopadhyay
Keyword(s):  
Hydrogen Bonding ◽  
Solid State ◽  
Dft Calculations ◽  
Mixed Valence ◽  
Halogen Bonding ◽  
Supramolecular Interactions ◽  
Hydrogen Bonding Interaction ◽  
Bonding Interaction ◽  
Solid State Structures ◽  
Theoretical Insight

Supramolecular interactions in the solid state structures of a mixed valence cobalt(ii/iii) complex and a cobalt(iii) complex have been studied using DFT calculations.

scholarly journals Crystal structure ofN,N′-dibenzyl-3,3′-dimethoxybenzidine

2018 ◽  
Vol 74 (3) ◽  
pp. 271-274
Author(s):  
Hansu Im ◽  
Jineun Kim ◽  
Changeun Sim ◽  
Tae Ho Kim
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Schiff Base ◽  
Hydrogen Bonds ◽  
Dft Calculations ◽  
Title Compound ◽  
Condensation Reaction ◽  
Asymmetric Unit ◽  
One Dimensional ◽  
Acidic Conditions

The title compound, (systematic name:N,N′-dibenzyl-3,3′-dimethoxy-1,1′-biphenyl-4,4′-diamine), C28H28N2O2, was synthesized by the reduction of a Schiff base preparedviaa condensation reaction betweeno-dianisidine and benzaldehyde under acidic conditions. The molecule lies on a crystallographic inversion centre so that the asymmetric unit contains one half-molecule. The biphenyl moiety compound is essentially planar. Two intramolecular N—H...O hydrogen bonds occur. The dihedral angle between the terminal phenyl and phenylene rings of a benzidine unit is 48.68 (6)°. The methylene C atom of the benzyl group is disordered over two sets of sites, with occupancy ratio 0.779 (18):0.221 (18). In the crystal, molecules are connected by hydrogen bonding betweeno-dianisidine O atoms and H atoms of the terminal benzyl groups, forming a one-dimensional ladder-like structure. In the data from DFT calculations, the central biphenyl showed a twisted conformation.

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