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 ◽  
...  

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...

2007 ◽  
Vol 63 (3) ◽  
pp. o1289-o1290 ◽  
Author(s):  
Jin-Zhou Li ◽  
Heng-Qiang Zhang ◽  
Hong-Xin Li ◽  
Pi-Zhi Che ◽  
Tian-Chi Wang

The crystal structure of the title compound, C18H11ClN2O4, contains intra- and intermolecular hydrogen bonds that link the ketone and hydroxyl groups. The intermolecular hydrogen bond results in the formation of a dimer with an R 2 2(12) graph-set motif.


2000 ◽  
Vol 55 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Teresa Borowiak ◽  
Irena Wolska ◽  
Artur Korzański ◽  
Wolfgang Milius ◽  
Wolfgang Schnick ◽  
...  

The crystal structures of two compounds containing enaminone heterodiene systems and forming intermolecular hydrogen bonds N-H·O are reported: 1) 3-ethoxycarbonyl-2-methyl-4-pyridone (hereafter ETPY) and 2) 3-ethoxycarbonyl-2-phenyl-6-methoxycarbonyl-5,6-di-hydro-4-pyridone (hereafter EPPY). The crystal packing is controlled by intermolecular hydro­ gen bonds N-H·O = C connecting the heteroconjugated enaminone groups in infinite chains. In ETPY crystals the intermolecular hydrogen bond involves the heterodienic pathway with the highest π-delocalization that is effective for a very short N·O distance of 2.701(9) Å (average from two molecules in the asymmetric unit). Probably due to the steric hindrance, the hydrogen bond in EPPY is formed following the heterodienic pathway that involves the ester C = O group, although π-delocalization along this pathway is less than that along the pyridone-part pathway resulting in a longer N·O distance of 2.886(3) Å


2000 ◽  
Vol 55 (8) ◽  
pp. 671-676 ◽  
Author(s):  
Maciej Kubicki ◽  
Teresa Borowiak ◽  
Wiesław Z. Antkowiak

Abstract The crystal structures of two isomeric compounds, 2-endo-hydroxybornane-3-endo-carboxylic acid and 2 -exo -hydroxybomane-3 -endo-carboxylic acid, have been determined by X-ray single crystal analysis. The only difference between these two compounds is the disposition of the 2-hydroxy group with respect to the bomane skeleton. Both compounds show quite different hydrogen bonding schemes. In the endo-hydroxy-endo-carboxy isomer there is one intramolecular and one intermolecular hydrogen bond, which connects molecules into infinite chains, while in the exo-hydroxy-endo-carboxy isomer there are two intermolecular hydrogen bonds that form a more stable architecture of two kinds of chains which interconnect to close rings comprising four molecules. Due to these differences the melting point of 2 is ca. 30° higher than for 1 .


2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Sergei Vdovenko ◽  
Igor Gerus ◽  
Elena Fedorenko ◽  
Valery Kukhar

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.


2021 ◽  
Vol 8 (9) ◽  
pp. 210565
Author(s):  
Yanchao Yin ◽  
Guoliang Zhang ◽  
Xianmang Xu ◽  
Peiyu Zhao ◽  
Liran Ma

Intermolecular hydrogen bonds are formed through the electrostatic attraction between the hydrogen nucleus on a strong polar bond and high electronegative atom with an unshared pair of electrons and a partial negative charge. It affects the physical and chemical properties of substances. Based on this, we presented a physical method to modulate intermolecular hydrogen bonds for not changing the physical–chemical properties of materials. The graphite and graphene are added into the glycerol, respectively, by being used as a viscosity reducer in this paper. The samples are characterized by Raman and 1H-nuclear magnetic resonance. Results show that intermolecular hydrogen bonds are adjusted by graphite or graphene. The rheology of glycerol is reduced to varying degrees. Transmission electron microscopes and computer simulation show that the spatial limiting action of graphite or graphene is the main cause of breaking the intermolecular hydrogen bond network structure. We hope this work reveals the potential interplay between nanomaterials and hydroxyl liquids, which will contribute to the field of solid–liquid coupling lubrication.


Author(s):  
Mikhail E. Minyaev ◽  
Ilya E. Nifant'ev ◽  
Alexander N. Tavtorkin ◽  
Sof'ya A. Korchagina ◽  
Shadana Sh. Zeynalova

Crystals of the title compound, [Li{OOP(O-2,6-iPr2C6H3)2}(CH3OH)3]·CH3OH or [Li(C24H34O4P)(CH3OH)3]·CH3OH, have been formed in the reaction between HOOP(O-2,6-iPr2C6H3)2and LiOH in methanol. The title compound is of interest as it represents the first reported crystal structure of the family of lithium phosphate diesters. The {Li(CH3OH)3[O2P(O-iPr2C6H3)2]} unit displays the Li atom in a slightly distorted tetrahedral coordination environment and exhibits one intramolecular O—H...O hydrogen bond between a coordinating methanol molecule and the terminal non-coordinating O atom of the phosphate group. The unit is connected with two non-coordinating methanol molecules through two intermolecular O—H...O hydrogen bonds, and with a neighbouring unit through two other O—H...O interactions. These intermolecular hydrogen bonds lead to the formation of infinite chains along [100]. There are no significant interactions between the chains.


2012 ◽  
Vol 68 (6) ◽  
pp. m820-m821 ◽  
Author(s):  
Małgorzata Sikorska ◽  
Maria Gazda ◽  
Jaroslaw Chojnacki

The title compound {systematic name: bis(μ2-dihydrogen 4-azaniumyl-1-hydroxybutane-1,1-diphosphonato)bis[aqua(dihydrogen 4-azaniumyl-1-hydroxybutane-1,1-diphosphonato)nickel(II)] dihydrate}, [Ni2(C4H12NO7P2)4(H2O)2]·2H2O, was synthesiized under hydrothermal conditions. Its structure is isotypic with the CoII analogue. The crystal structure is built up from centrosymmetric dinuclear complex molecules and the structure is reinforced by a net of intermolecular O—H...O and N—H...O hydrogen bonds. One water molecule is bound to the NiII atom in the octahedral coordination sphere, while the second is part of the intermolecular hydrogen-bond system.


2012 ◽  
Vol 68 (4) ◽  
pp. o1042-o1042 ◽  
Author(s):  
Huanzhi Xu ◽  
Jingya Sun

The title compound, C16H15Cl2N3O2·CH3OH, a Schiff base molecule, is prepared by the reaction of 3,5-dichlorosalicylaldehyde with 4-dimethylaminobenzohydrazide in methanol. The Schiff base molecule is approximately planar, with a mean deviation from the least-squares plane defined by the non-H atoms of 0.0452 (3) Å, and with a dihedral angle between the benzene rings of 4.2 (3)°. This planarity is assisted by the formation of an intramolecular O—H...N hydrogen bond. In the crystal, adjacent Schiff base molecules are linked by two methanol molecules through N—H...O and O—H...O hydrogen bonds, forming dimers.


2014 ◽  
Vol 70 (6) ◽  
pp. o702-o703 ◽  
Author(s):  
Thammarse S. Yamuna ◽  
Manpreet Kaur ◽  
Jerry P. Jasinski ◽  
H. S. Yathirajan

In the cation of the title salt, C8H13N4+·C4H3O4−, the piperazinium ring adopts a slightly distorteded chair conformation. In the crystal, a single strong O—H...O intermolecular hydrogen bond links the anions, forming chains along thec-axis direction. The chains of anions are linked by the cations,viaN—H...O hydrogen bonds, forming sheets parallel to (100). These layers are linked by weak C—H...O hydrogen bonds, forming a three-dimensional structure. In addition, there are weak π–π interactions [centroid–centroid distance = 3.820 (9) Å] present involving inversion-related pyrimidine rings.


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