scholarly journals C–H⋯F Hydrogen Bond and Integral Intensities of Vinyl C–H Vibtations in Push-Pull β-Dimethylaminotrifluoromethyl Ketone and Its Deuterated Analog

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Sergei Vdovenko ◽  
Igor Gerus ◽  
Elena Fedorenko ◽  
Valery Kukhar
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Dft Calculations ◽  
Intramolecular Hydrogen Bond ◽  
Infrared Spectra ◽  
Intermolecular Hydrogen Bond ◽  
Intermolecular Hydrogen Bonds ◽  
Accurate Analysis ◽  
Deuterated Analog ◽  
Intramolecular Hydrogen

The accurate analysis of infrared spectra (both wavenumbers and intensities) of (E)-4-(dimethylamino)-1,1,1-trifluorobut-3-en-2-one (DMTBN) and (E)-4-(hexadeutero-dimethylamino)-1,1,1-trifluorobut-3-en-2-one (d6-DMTBN) revealed that besides intramolecular hydrogen bond in the (EE) conformer, these enaminoketones form cyclic dimers between the (EZ) and (EE) conformers due to intermolecular hydrogen bonds, namely, O=C and . Evaluation of constant and enthalpy of formation of these H-bonds revealed that O=C bond has greater and more negative than bond (cf. 214.4 M−1, −21.7 kJ M−1dm3, and 16.4 M−1, −6.7 kJ M−1dm3, resp.). Consequently, stronger H-bond ⋯O=C is formed in the first place, whereas weaker H-bond is formed afterward. Moreover, formation of intermolecular hydrogen bond has influence on C–F vibrations, but analysis of this influence must take into account the fact that these vibrations in some cases are coupled with . True enthalpy of the equilibrium (EZ)⇌(EE) is positive (25.3 kJ M−1dm3), thus confirming results of DFT calculations, according to which the (EZ) conformer is more stable than the (EE) one.

scholarly journals N-[2-(Methylsulfanyl)phenyl]-2-sulfanylbenzamide

2012 ◽  
Vol 68 (8) ◽  
pp. o2400-o2400
Author(s):  
Chang-Chih Hsieh ◽  
Hon Man Lee ◽  
Yih-Chern Horng
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Intramolecular Hydrogen Bond ◽  
Title Compound ◽  
Aromatic Rings ◽  
Intermolecular Hydrogen Bonds ◽  
Methyl Group ◽  
Interplanar Angle ◽  
Compound C ◽  
Intramolecular Hydrogen

In the title compound, C14H13NOS2, the S atom with the methyl group is involved in an intramolecular hydrogen bond with the amido H atom. In the crystal, the sulfanyl H atoms form intermolecular hydrogen bonds with the O atoms, connecting the molecules into zigzag chains along thecaxis. The two aromatic rings exhibit a small interplanar angle of 16.03 (9)°.

Ethyl 1-[5-amino-1-tert-butyl-3-(methylsulfanyl)-1H-pyrazole-4-carbonyl]-5-methyl-3-(methylsulfanyl)-1H-pyrazole-4-carboxylate

2006 ◽  
Vol 62 (5) ◽  
pp. o1679-o1681
Author(s):  
Jun-Fei Li ◽  
Hai-Bin Song ◽  
You-Quan Zhu ◽  
Hua-Zheng Yang
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Intramolecular Hydrogen Bond ◽  
Membered Ring ◽  
Intermolecular Hydrogen Bonds ◽  
Tert Butyl ◽  
The Family ◽  
Title Molecule ◽  
Intramolecular Hydrogen

The title molecule, C17H25N5O3S2, belongs to the family of bis-heterocycles. In the crystal structure, there are one intra- and two intermolecular hydrogen bonds. One of the two pyrazole rings and the six-membered ring formed by the intramolecular hydrogen bond are approximately coplanar.

Solvent effects on the infrared spectra of anilines. VII. 2-Substituted 4-nitroanilines

1970 ◽  
Vol 23 (5) ◽  
pp. 947 ◽  
Author(s):  
LK Dyall
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Infrared Spectra ◽  
Solvent Effects ◽  
Intermolecular Hydrogen Bond ◽  
Lone Pair ◽  
Acceptor Molecule ◽  
Intramolecular Hydrogen Bonds ◽  
Intramolecular Hydrogen ◽  
Ortho Substituent

Measurements of N-H stretching frequencies of 4-nitroanilines in the presence of hydrogen bond acceptors show that the ease of forming a second intermolecular hydrogen bond in the presence of an ortho substituent decreases in the order hydrogen > methyl > bromo, methoxyl > nitro. This order demonstrates the importance of repulsions between lone pair orbitals on the ortho substituent and the acceptor molecule. Weak intramolecular hydrogen bonds are detected in 2-iodo- and 2-bromo-aniline, and such bonds can be strengthened by introduction of a 4-nitro substituent.

scholarly journals Intramolecular Hydrogen Bond Energy and Its Decomposition—O–H∙∙∙O Interactions

Crystals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 5
Author(s):  
Sławomir J. Grabowski
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Intramolecular Hydrogen Bond ◽  
Bond Energy ◽  
Decomposition Analysis ◽  
Energy Decomposition Analysis ◽  
Energy Decomposition ◽  
Intermolecular Hydrogen Bonds ◽  
Hydrogen Bond Energy ◽  
Intramolecular Hydrogen

The method to calculate the energy of intramolecular hydrogen bond is proposed and tested for a sample of malonaldehyde and its fluorine derivatives; the corresponding calculations were performed at the ωB97XD/aug-cc-pVTZ level. This method based on relationships found for related intermolecular hydrogen bonds is compared with other approaches which may be applied to estimate the intramolecular hydrogen bond energy. Particularly, methods based on the comparison of the system that contains the intramolecular hydrogen bond compared with corresponding conformations where such interaction does not occur are discussed. The function-based energy decomposition analysis, FB-EDA, of the intramolecular hydrogen bonds is also proposed here.

scholarly journals Crystal structure of 3-[({2-[bis(2-hydroxybenzyl)amino]ethyl}(2-hydroxybenzyl)amino)methyl]-2-hydroxy-5-methylbenzaldehyde

2014 ◽  
Vol 70 (12) ◽  
pp. 562-565
Author(s):  
Alexandra S. Fonseca ◽  
Adailton J. Bortoluzzi
Keyword(s):  
Molecular Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Intramolecular Hydrogen Bond ◽  
Intermolecular Hydrogen Bond ◽  
Phenol Group ◽  
The Third ◽  
Graph Set ◽  
Title Molecule ◽  
Intramolecular Hydrogen

The non-symmetric title molecule, C32H34N2O5, is based on a tetrasubstituted ethylenediamine backbone. The molecular structure consists of three hydroxybenzyl groups and one 2-hydroxy-5-methylbenzaldehyde group bonded to the N atoms of the diamine unit. The ethylenediamine skeleton shows a regular extended conformation, while the spatial orientation of the phenol arms is governed by hydrogen bonds. In the 2-hydroxy-5-methylbenzaldehyde group, an intramolecularS(6) O—H...O hydrogen bond is observed between the alcohol and aldehyde functions, and the neighbouring phenol arm participates in an intramolecularS(6) O—H...N hydrogen bond. The third phenol group is involved in a bifurcated intramolecular hydrogen bond with graph-set notationS(6) for O—H...N and O—H...O intramolecular hydrogen bonds between neighbouring amine and phenol arms, respectively. Finally, the fourth phenol group acts as an acceptor in a bifurcated intramolecular hydrogen bond and also acts as donor in an intermolecular hydrogen bond, which connects inversion-related molecules into dimers withR44(8) ring motifs.

Chiral Recognition in Jet-Cooled Complexes

2004 ◽  
Vol 57 (12) ◽  
pp. 1149 ◽  
Author(s):  
Nathalie Seurre ◽  
Katia Le Barbu-Debus ◽  
Françoise Lahmani ◽  
Nicole Borho ◽  
Martin A. Suhm ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Dft Calculations ◽  
Chiral Recognition ◽  
Abundant Species ◽  
Laser Induced Fluorescence ◽  
Chiral Discrimination ◽  
Intermolecular Hydrogen Bonds ◽  
Methyl Lactate ◽  
Intramolecular Hydrogen

Jet-cooled complexes formed between a chiral probe [(±)-2-naphthyl-1-ethanol] and chiral bifunctional partners that show an intramolecular hydrogen bond have been studied by laser-induced fluorescence and IR fluorescence-dip spectroscopy as well as with DFT calculations. Chiral discrimination results in a chirality-dependent competition between the intramolecular and the intermolecular hydrogen bonds. In the case of (±)-methyl lactate, this competition manifests itself in the size of the formed adducts. In particular, while 1 : 1 complexes are the most abundant species observed when (R)-2-naphthyl-1-ethanol is mixed with (S)-methyl lactate, they are absent in the case of the SS mixture, which only forms 1 : 2 adducts.

Intermolecular Hydrogen Bond Plays a Determining Role in Product Selection of Surface Confined Schiff-base Reaction

2021 ◽  
Author(s):  
Huamei Chen ◽  
Guangyuan Feng ◽  
Qiu Liang ◽  
Enbing Zhang ◽  
Yongtao Shen ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Schiff Base ◽  
Hydrogen Bonds ◽  
Relative Abundance ◽  
Intermolecular Hydrogen Bond ◽  
Intermolecular Hydrogen Bonds ◽  
Product Selection ◽  
Selection Of

Herein, we illustrate how the cooperation of intermolecular hydrogen bonds and conformation flexibility leads to the formation of diverse complex covalent nanostructures on the surface, while the relative abundance of...

Stereochemistry-dependent hydrogen bonds stabilise stacked conformations in jet-cooled cyclic dipeptides: (LD) vs. (LL) cyclo tyrosine–tyrosine

2018 ◽  
Vol 212 ◽  
pp. 399-419 ◽  
Author(s):  
Feriel BenNasr ◽  
Ariel Pérez-Mellor ◽  
Ivan Alata ◽  
Valeria Lepere ◽  
Nejm-Eddine Jaïdane ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Intramolecular Hydrogen Bond ◽  
Cyclic Dipeptides ◽  
Intramolecular Hydrogen

Changing the chirality of one residue prevents the formation of an OH⋯O intramolecular hydrogen bond in cyclo di-tyrosine.

Intramolecular hydrogen bond-induced high chemical stability of metal–organic frameworks

2020 ◽  
Vol 7 (19) ◽  
pp. 3548-3554
Author(s):  
Keke Wang ◽  
Qunmin Wang ◽  
Xiong Wang ◽  
Mei Wang ◽  
Qin Wang ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Intramolecular Hydrogen Bond ◽  
Chemical Stability ◽  
Metal Organic Frameworks ◽  
Carboxyl Groups ◽  
High Chemical ◽  
Metal Organic ◽  
Intramolecular Hydrogen ◽  
High Chemical Stability

Intramolecular hydrogen bonds in ligands restrict the rotation of carboxyl groups and consequently enhance the chemical stability of MOFs.

True symmetry or pseudosymmetry: 5-amino-1-(4-methylphenylsulfonyl)-4-pyrazolin-3-one and a comparison with its 1-phenylsulfonyl analogue

2012 ◽  
Vol 69 (1) ◽  
pp. 90-92 ◽  
Author(s):  
Galal H. Elgemeie ◽  
Shahinaz H. Sayed ◽  
Peter G. Jones
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Intramolecular Hydrogen Bond ◽  
Title Compound ◽  
Acta Cryst ◽  
Interplanar Angle ◽  
Phenyl Derivative ◽  
Compound C ◽  
Independent Molecules ◽  
Intramolecular Hydrogen

The title compound, C10H11N3O3S, (I), crystallizes as the NH tautomer. The two rings subtend an interplanar angle of 72.54 (4)°. An intramolecular hydrogen bond is formed from the NH2group to a sulfonyl O atom. The molecular packing involves layers of molecules parallel to thebcplane atx≃ 0, 1etc., with two classical linear hydrogen bonds (amino–sulfonyl and pyrazoline–carbonyl N—H...O) and a further interaction (amino–sulfonyl N—H...O) completing a three-centre system with the intramolecular contact. The analogous phenyl derivative, (II) [Elgemeie, Hanfy, Hopf & Jones (1998).Acta Cryst.C54, 136–138], crystallizes with essentially the same unit cell and packing pattern, but with two independent molecules that differ significantly in the orientation of the phenyl groups. The space group isP21/cfor (I) butP21for (II), which is thus a pseudosymmetric counterpart of (I).

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