A comparative study on the dynamics of epimeric 1-hydroxymethyl quinolizidines: II. The solvent and concentration dependence of the association properties

1988 ◽  
Vol 66 (9) ◽  
pp. 2166-2171 ◽  
Author(s):  
K. Kulińska ◽  
M. Wiewiórowski
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Intermolecular Hydrogen Bond ◽  
Chloroform Solution ◽  
Weak Acid ◽  
Hydroxyl Group ◽  
Intermolecular Hydrogen Bonding ◽  
Concentrated Solutions ◽  
Electron Pairs ◽  
Solvent Molecules

The homo and heteroassociation patterns of lupinine and epilupinine in different solvents and at various concentrations have been studied. In n-hexane, n-heptane, CCl4, and C2H4Cl2 solvents, lupinine monomers with an intramolecular OH … N hydrogen bond dominate over homoassociates with an OH … O′ intermolecular hydrogen bond even in concentrated solutions. Homoassociation of lupinine by intermolecular OH … N′ hydrogen bonding is observed only in saturated solutions. In chloroform solution any intermolecular homoassociation is effectively blocked because of significant affinity of chloroform molecules acting as a weak acid toward the free electron pairs of the oxygen atom from the hydroxyl group that would be otherwise engaged in intramolecular OH … N hydrogen bonding. Epilupinine in n-hexane, n-heptane, CCl4, C2H4Cl2, and chloroform solutions forms possible homoassociates both by OH … N′ and OH … O′ intermolecular hydrogen bonding. In dioxane-d8, DMSO, and D2O solvents both lupinine and epilupinine form heteroassociates with solvent molecules.

Mechanisms of long-range 13C, 13C spin–spin coupling in thioanisole and its derivatives. Conformational applications

1988 ◽  
Vol 66 (5) ◽  
pp. 1229-1238 ◽  
Author(s):  
Ted Schaefer ◽  
Glenn H. Penner
Keyword(s):  
Hydrogen Bond ◽  
Long Range ◽  
Intermolecular Hydrogen Bond ◽  
Lone Pair ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Hydroxyl Group ◽  
Trans Orientation ◽  
Solvent Molecules ◽  
Spin Spin Coupling

The 13C nuclear magnetic resonance chemical shifts and the long-range 13C,13C spin–spin coupling constants are reported for 23 thioanisole derivatives enriched in 13C at the methyl position. For para and meta substituted thioanisole derivatives, nJ(C,C) (n being the formal number of bonds intervening between the coupled nuclei) can be related to functions of the angle by which the thiomethyl group twists out of the aromatic plane. For n = 3,4,5, the ensuing relationships yield estimates of the twofold barriers to rotation about the C(1)—S bond. The barrier is lower in ethyl phenyl sulfide than in thioanisole derivatives. Complications arise for ortho substituted thioanisole derivatives but estimates of the torsional motion about the C(1)—S bond can be obtained from the observed nJ(C,C). Among the complications is the expected fact that 3J(C,C), which is shown to be larger in the cis than the trans orientation of the intervening bonds ("anti-Karplus" behaviour), is perturbed by the substituent attached to the coupled nucleus. It is confirmed that in 2-hydroxythioanisole the thiomethyl group is oriented effectively perpendicular to the benzene plane, attributable to a stereospecific hydrogen bond between the hydroxyl group and the 3p lone-pair on the sulfur atom. In acetone-d6 solution, an equilibrium exists between this conformation and one in which an intermolecular hydrogen bond exists with solvent molecules. In the latter, the thiomethyl group prefers a coplanar orientation. In 2-aminothioanisole, the thiomethyl group twists out of the plane by about 60° so as to optimize the N—H … 3p interaction. This twist angle is changed very little in acetone-d6 solution because the second N—H bond can hydrogen bond to the solvent molecules without disrupting the intramolecular N—H … 3p interaction. It is also shown that the chemical shift of the 13C nucleus in the methyl group is a good conformational indicator in meta and para substituted thioanisoles. Therefore it can be used as such for molecules in which nJ(C,C) is difficult to find, in 1,4-dithiomethylbenzene, for example.

scholarly journals Structure Elucidation of N-aryl-2-chloro-3-oxobutanamides with respect to intra- and intermolecular hydrogen bonding

2002 ◽  
Vol 2002 (1) ◽  
pp. 13-14 ◽  
Author(s):  
Petra Frohberg ◽  
Guntram Drutkowski ◽  
Christoph Wagner ◽  
Olaf Lichtenberger
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Solid State ◽  
Structure Elucidation ◽  
Intermolecular Hydrogen Bond ◽  
Carbonyl Oxygen ◽  
Intermolecular Hydrogen Bonding ◽  
Intramolecular Association

In general, N-aryl-2-chloro-3-oxobutanamides form in solid state an intermolecular hydrogen bond between the anilide hydrogen and the anilide carbonyl oxygen of a neighbouring molecule, which is disrupted in solution. An intramolecular association could not be detected.

Investigation of Hydrogen Bonding Interaction between Bolaform Schiff Bases with Barbituric Acid by HPLC

2011 ◽  
Vol 356-360 ◽  
pp. 48-51
Author(s):  
Qi Tong ◽  
Ti Feng Jiao
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Liquid Chromatography ◽  
Schiff Bases ◽  
Barbituric Acid ◽  
Flexible Structure ◽  
Intermolecular Hydrogen Bonding ◽  
Acid Molecule ◽  
Hydrogen Bonding Interaction ◽  
Bonding Interaction

In order to investigate the intermolecular hydrogen bonding of special amphiphiles, two bolaform amphiphilic Schiff bases (GN1 and GN2) with different hydrophilic spacers were designed, and their interaction with barbituric acid were tested by liquid chromatography. The chromatographic properties showed that both the Schiff bases showed hydrogen bonding interaction with barbituric acid. In addition, the influence of various detectors was also studied on both cases. Experimental results show that the test with FLD showed better determination than other detectors. It is proposed that due to the directionality and strong matching of hydrogen bond, one barbituric acid molecule can be encapsulated into the intramolecular area of GN1, while two barbituric acid molecules were trapped into the GN2 molecule through intermolecular H-bonds for GN2 due to the long spacer and flexible structure. A rational complex mode was proposed.

THE STUDY OF HYDROGEN BONDING AND RELATED PHENOMENA BY ULTRAVIOLET LIGHT ABSORPTION: PART IV. INTERMOLECULAR HYDROGEN BONDING IN ANILINES AND PHENOLS

1960 ◽  
Vol 38 (6) ◽  
pp. 896-910 ◽  
Author(s):  
J. C. Dearden ◽  
W. F. Forbes
Keyword(s):  
Hydrogen Bonding ◽  
Ultraviolet Light ◽  
Light Absorption ◽  
Intermolecular Hydrogen Bonding ◽  
Solvent Molecules

Intermolecular hydrogen bonding in anilines and phenols can be subdivided into bonding involving solute molecules only, and into bonding involving both solute and solvent molecules. Interactions which do not involve hydrogen bonding are also possible between solute and solvent molecules. Spectral effects which may be associated with each of these interactions are described and discussed for anilines and phenols. By noting the effects of substituents on the various interactions, tentative conclusions can be deduced concerning the nature of these interactions.

Hydrogen bond-modulated molecular packing and its applications in high-performance non-doped organic electroluminescence

2020 ◽  
Vol 7 (10) ◽  
pp. 2734-2740
Author(s):  
Yizhong Shi ◽  
Kai Wang ◽  
Youichi Tsuchiya ◽  
Wei Liu ◽  
Takeshi Komino ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
High Performance ◽  
Molecular Packing ◽  
Intermolecular Hydrogen Bonding ◽  
Supramolecular Framework ◽  
Organic Electroluminescence

Suitable intermolecular hydrogen bonding enables the formation of a fixed 3D supramolecular framework and suppresses the exciton nonradiative decays and quenching.

Hydrogen-bond patterns in 1,4-dihydro-2,3-quinoxalinediones: ligands for the glycine modulatory site on the NMDA receptor

1996 ◽  
Vol 52 (3) ◽  
pp. 487-499 ◽  
Author(s):  
M. Kubicki ◽  
T. W. Kindopp ◽  
M. V. Capparelli ◽  
P. W. Codding
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Binding Site ◽  
Three Dimensional ◽  
Hydrogen Bonding Pattern ◽  
Wide Range ◽  
Show Evidence ◽  
Additional Hydrogen Bond ◽  
Hydrogen Bond Patterns ◽  
Solvent Molecules

The crystal structures of five 1,4-dihydro-2,3-quinoxalinediones, antagonists of the NMDA modulatory glycine binding site on the excitary amino acid (EAA) receptor complex, have been determined: (I) 6,7-dinitro-1,4-dihydro-2,3-quinoxalinedione (DNQX); (II) 5,7-dinitro-1,4-dihydro-2,3-quinoxalinedione (MNQX); (III) 6-nitro-1,4-dihydro-2,3-quinoxalinedione hydrate; (IV) 6,7-dichloro-1,4-dihydro-2,3-quinoxalinedione; (V) 5,7-dichloro-1,4-dihydro-2,3-quinoxalinedione dimethylformamide. The crystal structure of the most active compound (II) contains a unique intramolecular N—H...O(NO2) hydrogen bond, which may be important for activity, as semiempirical calculations show that this bond is stable over a wide range of dihedral angles between the planes of the molecule and of the nitro group. In the other compounds the intermolecular hydrogen bonds connect molecules into three-dimensional networks. In compounds (I), (III) and (IV) head-to-tail: π-stacking is found between molecules connected by a center of symmetry. The geometries of the hydrogen-bonded —NH—C=O fragments show evidence of π-cooperativity or resonance-assisted hydrogen bonding. Graph-set analysis of the hydrogen-bond patterns of quinoxalinedione derivatives shows a tendency to form two types of hydrogen-bonding motifs: a centrosymmetric dimeric ring and an infinite chain. Even though this pattern may be modified by the presence of additional hydrogen-bond acceptors and/or donors, as well as by solvent molecules, general similarities have been found. Comparison of all quinoxalinedione structures suggests that the hydrogen-bonding pattern necessary for the biological activity at the glycine binding site contains one donor and two acceptors.

Weak intramolecular and intermolecular hydrogen bonding of benzyl alcohol, 2-phenylethanol and 2-phenylethylamine in the adsorption on graphitized thermal carbon black

2015 ◽  
Vol 17 (37) ◽  
pp. 24282-24293 ◽  
Author(s):  
V. V. Varfolomeeva ◽  
A. V. Terentev
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Carbon Black ◽  
Benzyl Alcohol ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Intermolecular Hydrogen Bonding ◽  
Weak Hydrogen Bond ◽  
Graphitized Thermal Carbon Black ◽  
Flexible Molecules

The present paper discusses the contemporary state of the studies of the weak hydrogen bond contribution to the adsorption of flexible molecules. We formulated the problems which can be solved today only using the NCI method and quantum chemical calculations.

Hydrogen-Bonding Schemes of Galactonic Acid Hydrazide and its Hemihydrate

1997 ◽  
Vol 53 (3) ◽  
pp. 490-497 ◽  
Author(s):  
C. André ◽  
P. Luger ◽  
J.-H. Fuhrhop ◽  
F. Hahn
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Crystal Packing ◽  
Scintillation Counter ◽  
Acid Hydrazide ◽  
Coordination Shell ◽  
Hydroxyl Group ◽  
Free Sugar ◽  
Imaging Plate

The crystal structure of L-galactonic acid hemihydrate was determined using data obtained from an imaging plate detector (Stoe IPDS), whereas a conventional scintillation counter was used for the elucidation of the crystal structure of anhydrous D-galactonic acid. The H atom of the terminal hydroxyl group of the water-free sugar participates only in an intramolecular hydrogen bond with the preterminal O atom. This hydrogen bond is part of an antidromic hydrogen-bonding cycle. The hydrogen-bonding scheme of the hemihydrate is very intricate due to the occurrence of two independent molecules and the incorporated water, whose coordination shell can be described by a distorted tetrahedron. One of the hydrogen-bond chains observed in the structure of the hemihydrate is infinite, forming a spiral running in the a direction. The crystal packing of both compounds displays a herringbone arrangement. However, the tilt angle between molecules in different herringbone halves is by far smaller in the structure of the hydrated sugar than in the water-free compound (~ 60 versus 96°).

2,4-Dibenzoyl-3,5-bis(4-methoxylphenyl)-1-phenylcyclohexanol

2006 ◽  
Vol 62 (4) ◽  
pp. o1631-o1632 ◽  
Author(s):  
Xinxiang Luo ◽  
Zixing Shan
Keyword(s):  
Hydrogen Bonding ◽  
Title Compound ◽  
Chair Conformation ◽  
Membered Ring ◽  
Hydroxyl Group ◽  
Intermolecular Hydrogen Bonding ◽  
Compound C

The title compound, C40H36O5, was synthesized from p-anisaldehyde and acetophenone. The central six-membered ring adopts a chair conformation and most of the bulky side groups are located in equatorial positions. The hydroxyl group is involved in weak intra- and intermolecular hydrogen bonding.

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