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.

THE STUDY OF HYDROGEN BONDING AND RELATED PHENOMENA BY ULTRAVIOLET LIGHT ABSORPTION: PART I. INTRODUCTION

1958 ◽  
Vol 36 (1) ◽  
pp. 180-188 ◽  
Author(s):  
W. F. Forbes ◽  
J. F. Templeton
Keyword(s):  
Hydrogen Bonding ◽  
Environmental Factors ◽  
Environmental Effects ◽  
Light Absorption ◽  
Bond Formation ◽  
Benzoic Acids ◽  
Intermolecular Hydrogen Bonding ◽  
Dimer Formation ◽  
Factors Affecting ◽  
Solvent Molecules

Hydrogen bonding, which is known to give rise to dimer formation in benzoic acids and similar compounds, may affect solution spectra by intermolecular and by intramolecular bond formation. Generally environmental factors affecting absorption spectra can be conveniently divided into three types: intermolecular hydrogen bonding between solute molecules only; intermolecular hydrogen bonding between solute and solvent molecules; and environmental effects not involving the formation of hydrogen bonds.Distinct evidence for these types of interaction is deduced from ultraviolet spectra, and various implications of the spectral analyses are discussed.

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.

Chiral anionic layers in tartramide spiroborate salts and variable solvation for [NR 4][B(TarNH2)2] (R = Et, Pr or Bu)

2020 ◽  
Vol 76 (7) ◽  
pp. 695-705
Author(s):  
Aristyo Soecipto ◽  
Lawrence W.-Y. Wong ◽  
Herman H.-Y. Sung ◽  
Ian D. Williams
Keyword(s):  
Hydrogen Bonding ◽  
Self Assembly ◽  
Interfacial Area ◽  
Intermolecular Hydrogen Bonding ◽  
Two Dimensional ◽  
Salt Hydrate ◽  
Anion Layer ◽  
Cation Layer ◽  
Layer Structures ◽  
Solvent Molecules

The spiroborate anion, namely, 2,3,7,8-tetracarboxamido-1,4,6,9-tetraoxa-5λ4-boraspiro[4.4]nonane, [B(TarNH2)2]−, derived from the diol L-tartramide TarNH2, [CH(O)(CONH2)]2, shows a novel self-assembly into two-dimensional (2D) layer structures in its salts with alkylammonium cations, [NR 4]+ (R = Et, Pr and Bu), and sparteinium, [HSpa]+, in which the cations and anions are segregated. The structures of four such salts are reported, namely, the tetrapropylazanium salt, C12H28N+·C8H12BN4O8 −, the tetraethylazanium salt hydrate, C8H20N+·C8H12BN4O8 −·6.375H2O, the tetrabutylazanium salt as the ethanol monosolvate hemihydrate, C16H36N+·C8H12BN4O8 −·C2H5OH·0.5H2O, and the sparteinium (7-aza-15-azoniatetracyclo[7.7.1.02,7.010,15]heptadecane) salt as the ethanol monosolvate, C15H27N2 +·C8H12BN4O8 −·C2H5OH. The 2D anion layers have preserved intermolecular hydrogen bonding between the amide groups and a typical metric repeat of around 10 × 15 Å. The constraint of matching the interfacial area organizes the cations into quite different solvated arrangements, i.e. the [NEt4] salt is highly hydrated with around 6.5H2O per cation, the [NPr4] salt apparently has a good metric match to the anion layer and is unsolvated, whilst the [NBu4] salt is intermediate and has EtOH and H2O in its cation layer, which is similar to the arrangement for the chiral [HSpa]+ cation. This family of salts shows highly organized chiral space and offers potential for the resolution of both chiral cations and neutral chiral solvent molecules.

scholarly journals Palladium(II) complexes of a bridging amine bis(phenolate) ligand featuring κ2 and κ3 coordination modes

2019 ◽  
Vol 75 (8) ◽  
pp. 1265-1269 ◽  
Author(s):  
Brendan J. Graziano ◽  
Bradley M. Wile ◽  
Matthias Zeller
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Planar Geometry ◽  
Intermolecular Hydrogen Bonding ◽  
Coordination Modes ◽  
Methyl Methyl ◽  
Ethyl Methyl ◽  
Square Planar ◽  
Solvent Molecules ◽  
Insight Into

Bidentate and tridentate coordination of a 2,4-di-tert-butyl-substituted bridging amine bis(phenolate) ligand to a palladium(II) center are observed within the same crystal structure, namely dichlorido({6,6′-[(ethane-1,2-diylbis(methylazanediyl)]bis(methylene)}bis(2,4-di-tert-butylphenol))palladium(II) chlorido(2,4-di-tert-butyl-6-{[(2-{[(3,5-di-tert-butyl-2-hydroxyphenyl)methyl](methyl)amino}ethyl)(methyl)amino]methyl}phenolato)palladium(II) methanol 1.685-solvate 0.315-hydrate, [PdCl2(C34H56N2O2)][PdCl(C34H55N2O2)]·1.685CH3OH·0.315H2O. Both complexes exhibit a square-planar geometry, with unbound phenol moieties participating in intermolecular hydrogen bonding with co-crystallized water and methanol. The presence of both κ2 and κ3 coordination modes arising from the same solution suggest a dynamic process in which phenol donors may coordinate or dissociate from the metal center, and offers insight into catalyst speciation throughout Pd-mediated processes. The unit cell contains dichlorido({6,6′-[(ethane-1,2-diylbis(methylazanediyl)]bis(methylene)}bis(2,4-di-tert-butylphenol))palladium(II), {(L 2)PdCl2}, and chlorido(2,4-di-tert-butyl-6-{[(2-{[(3,5-di-tert-butyl-2-hydroxyphenyl)methyl](methyl)amino}ethyl)(methyl)amino]methyl}phenolato)palladium(II), {(L 2 X)PdCl}, molecules as well as fractional water and methanol solvent molecules.

Effects of Multiple Binding Sites on Studies of Hydrogen Bonding between Nitroxide Radicals and Solvent Molecules

1993 ◽  
Vol 58 (1) ◽  
pp. 47-52 ◽  
Author(s):  
Imad Al-Bala'a ◽  
Richard D. Bates
Keyword(s):  
Hydrogen Bonding ◽  
Magnetic Resonance ◽  
Binding Site ◽  
Binding Sites ◽  
Hyperfine Coupling Constant ◽  
Hydrogen Donor ◽  
Complex Formation Constants ◽  
Multiple Binding Sites ◽  
Multiple Binding ◽  
Solvent Molecules

The role of more than one binding site on a nitroxide free radical in magnetic resonance determinations of the properties of the complex formed with a hydrogen donor is examined. The expression that relates observed hyperfine couplings in EPR spectra to complex formation constants and concentrations of each species in solution becomes much more complex when multiple binding sites are present, but reduces to a simpler form when binding at the two sites occurs independently and the binding at the non-nitroxide site does not produce significant differences in the hyperfine coupling constant in the complexed radical. Effects on studies of hydrogen bonding between multiple binding site nitroxides and hydrogen donor solvent molecules by other magnetic resonance methods are potentially more extreme.

scholarly journals Exploring the Structural Chemistry of Pyrophosphoramides: N,N′,N″,N‴-Tetraisopropylpyrophosphoramide

Chemistry ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 149-163
Author(s):  
Duncan Micallef ◽  
Liana Vella-Zarb ◽  
Ulrich Baisch
Keyword(s):  
Crystal Structure ◽  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Hydrogen Bonding ◽  
Nmr Spectroscopy ◽  
Ir Spectroscopy ◽  
Room Temperature ◽  
Intermolecular Hydrogen Bonding ◽  
X Ray Diffraction ◽  
X Ray

N,N′,N″,N‴-Tetraisopropylpyrophosphoramide 1 is a pyrophosphoramide with documented butyrylcholinesterase inhibition, a property shared with the more widely studied octamethylphosphoramide (Schradan). Unlike Schradan, 1 is a solid at room temperature making it one of a few known pyrophosphoramide solids. The crystal structure of 1 was determined by single-crystal X-ray diffraction and compared with that of other previously described solid pyrophosphoramides. The pyrophosphoramide discussed in this study was synthesised by reacting iso-propyl amine with pyrophosphoryl tetrachloride under anhydrous conditions. A unique supramolecular motif was observed when compared with previously published pyrophosphoramide structures having two different intermolecular hydrogen bonding synthons. Furthermore, the potential of a wider variety of supramolecular structures in which similar pyrophosphoramides can crystallise was recognised. Proton (1H) and Phosphorus 31 (31P) Nuclear Magnetic Resonance (NMR) spectroscopy, infrared (IR) spectroscopy, mass spectrometry (MS) were carried out to complete the analysis of the compound.

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