scholarly journals Solid-State 17 O NMR Reveals Hydrogen-Bonding Energetics: Not All Low-Barrier Hydrogen Bonds Are Strong

2017 ◽  
Vol 129 (22) ◽  
pp. 6262-6266 ◽  
Author(s):  
Jiasheng Lu ◽  
Ivan Hung ◽  
Andreas Brinkmann ◽  
Zhehong Gan ◽  
Xianqi Kong ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Solid State ◽  
Hydrogen Bonds ◽  
Low Barrier Hydrogen Bonds

scholarly journals Solid-State 17 O NMR Reveals Hydrogen-Bonding Energetics: Not All Low-Barrier Hydrogen Bonds Are Strong

2017 ◽  
Vol 56 (22) ◽  
pp. 6166-6170 ◽  
Author(s):  
Jiasheng Lu ◽  
Ivan Hung ◽  
Andreas Brinkmann ◽  
Zhehong Gan ◽  
Xianqi Kong ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Solid State ◽  
Hydrogen Bonds ◽  
Low Barrier Hydrogen Bonds

scholarly journals Temperature-Dependent Solid-State NMR Proton Chemical-Shift Values and Hydrogen Bonding

2021 ◽  
Author(s):  
Alexander A. Malär ◽  
Laura A. Völker ◽  
Riccardo Cadalbert ◽  
Lauriane Lecoq ◽  
Matthias Ernst ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Hydrogen Bonding ◽  
Solid State ◽  
Chemical Shift ◽  
Hydrogen Bonds ◽  
Solid State Nmr ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Proton Chemical Shift ◽  
Temperature Dependent

Temperature-dependent NMR experiments are often complicated by rather long magnetic-field equilibration times, for example occurring upon a change of sample temperature. We demonstrate that the fast temporal stabilization of the magnetic field can be achieved by actively stabilizing the temperature which allows to quantify the weak temperature dependence of the proton chemical shift which can be diagnostic for the presence of hydrogen bonds. Hydrogen bonding plays a central role in molecular recognition events from both fields, chemistry and biology. Their direct detection by standard structure determination techniques, such as X-ray crystallography or cryo-electron microscopy, remains challenging due to the difficulties of approaching the required resolution, on the order of 1 Å. We herein explore a spectroscopic approach using solid-state NMR to identify protons engaged in hydrogen bonds and explore the measurement of proton chemical-shift temperature coefficients. Using the examples of a phosphorylated amino acid and the protein ubiquitin, we show that fast Magic-Angle Spinning (MAS) experiments at 100 kHz yield sufficient resolution in proton-detected spectra to quantify the rather small chemical-shift changes upon temperature variations.<br>

The influence of hydrogen bonding on the character of N—H and C=O stretching modes in 2-thiopyrrole-1,2-dicarboximide

1984 ◽  
Vol 62 (9) ◽  
pp. 1845-1849 ◽  
Author(s):  
Shanker Ram
Keyword(s):  
Hydrogen Bonding ◽  
Transition Temperature ◽  
Solid State ◽  
Hydrogen Bonds ◽  
Spectral Data ◽  
Infrared Spectra ◽  
Cyclic Dimer ◽  
Dilute Solutions ◽  
Two Phases ◽  
Thermodynamical Functions

The infrared spectra (200–4000 cm−1) of 2-thiopyrrole-1,2-dicarboximide (TPH) in solid and solution forms have been measured as a function of temperature, and a direct correlation has been obtained between the two phases and the type and extent of hydrogen bonding. It is suggested that TPH exists as cyclic dimer in the solid state (below 310 K) and in dilute solutions by the formation of two equivalent hydrogen bonds. At the transition temperature, ~310 K, the cyclic dimer undergoes to the open-cyclic dimer and persists in this structure till 410 K. In addition, the thermodynamical functions ΔH0, and ΔS0 have been estimated using the spectral data in solution.

The design of artificial receptors for complexation and controlled aggregation

1993 ◽  
Vol 345 (1674) ◽  
pp. 57-66 ◽  
Keyword(s):  
Hydrogen Bonding ◽  
Solid State ◽  
Complex Formation ◽  
Hydrogen Bonds ◽  
Synthetic Receptors ◽  
Polar Solvents ◽  
Artificial Receptors ◽  
Hydrogen Bonding Interactions ◽  
Number Of Factors ◽  
Network Of Hydrogen Bonds

Simple synthetic receptors have been developed that function via directed hydrogen bonding interactions in highly competitive solvents. Strong binding of this type in polar solvents may be due to a number of factors including favourable secondary hydrogen bonding interactions between the carboxylate and urea, the use of charged H-bond acceptors, an inefficient solvation of the closely spaced H-bond donor sites in the urea, and an entropically favourable release of solvent and/or counterion molecules on complex formation. We also demonstrate that these types of interactions can be used to induce, both in solution and the solid state, discrete 2 + 2 aggregates stabilized by a network of hydrogen bonds.

Hydrogen/deuterium isotope effects on the 15N NMR chemical shifts and geometries of low-barrier hydrogen bonds in the solid state

1996 ◽  
Vol 378 (1) ◽  
pp. 11-16 ◽  
Author(s):  
Hans Benedict ◽  
Christoph Hoelger ◽  
Francisco Aguilar-Parrilla ◽  
Wolf-Peter Fehlhammer ◽  
Martin Wehlan ◽  
...  
Keyword(s):  
Solid State ◽  
Hydrogen Bonds ◽  
Chemical Shifts ◽  
Isotope Effects ◽  
15N Nmr ◽  
Nmr Chemical Shifts ◽  
Hydrogen Deuterium ◽  
Deuterium Isotope Effects ◽  
Low Barrier Hydrogen Bonds

scholarly journals Exploration and exploitation of homologous series of bis(acrylamido)alkanes containing pyridyl and phenyl groups: β-sheetversustwo-dimensional layers in solid-state photochemical [2 + 2] reactions

IUCrJ ◽  
2015 ◽  
Vol 2 (5) ◽  
pp. 523-533 ◽  
Author(s):  
Mousumi Garai ◽  
Kumar Biradha
Keyword(s):  
Hydrogen Bonding ◽  
Solid State ◽  
Hydrogen Bonds ◽  
Single Crystal ◽  
Crystal Structures ◽  
Homologous Series ◽  
Bonding Layer ◽  
Two Dimensional ◽  
Systematic Analysis ◽  
Small Change

The homologous series of phenyl and pyridyl substituted bis(acrylamido)alkanes have been synthesized with the aim of systematic analysis of their crystal structures and their solid-state [2 + 2] reactivities. The changes in the crystal structures with respect to a small change in the molecular structure, that is by varying alkyl spacers between acrylamides and/or by varying the end groups (phenyl, 2-pyridyl, 3-pyridyl, 4-pyridyl) on the C-terminal of the amide, were analyzed in terms of hydrogen-bonding interference (N—H...NpyversusN—H...O=C) and network geometries. In this series, a greater tendency towards the formation of N—H...O hydrogen bonds (β-sheets and two-dimensional networks) over N—H...N hydrogen bonds was observed. Among all the structures seven structures were found to have the required alignments of double bonds for the [2 + 2] reaction such that the formations of single dimer, double dimer and polymer are facilitated. However, only four structures were found to exhibit such a solid-state [2 + 2] reaction to form a single dimer and polymers. The two-dimensional hydrogen-bonding layerviaN—H...O hydrogen bonds was found to promote solid-state [2 + 2] photo-polymerization in a single-crystal-to-single-crystal manner. Such two-dimensional layers were encountered only when the spacer between acryl amide moieties is butyl. Only four out of the 16 derivatives were found to form hydrates, two each from 2-pyridyl and 4-pyridyl derivatives. The water molecules in these structures govern the hydrogen-bonding networks by the formation of an octameric water cluster and one-dimensional zigzag water chains. The trends in the melting points and densities were also analyzed.

Structure and hydrogen bonding in 2,4-dihydroxybenzoic acid at 90, 100, 110 and 150 K; a theoretical and single-crystal X-ray diffraction study

2007 ◽  
Vol 63 (2) ◽  
pp. 303-308 ◽  
Author(s):  
Andrew Parkin ◽  
Martin Adam ◽  
Richard I. Cooper ◽  
Derek S. Middlemiss ◽  
Chick C. Wilson
Keyword(s):  
Hydrogen Bonding ◽  
Solid State ◽  
Hydrogen Bonds ◽  
X Ray Diffraction ◽  
Dihydroxybenzoic Acid ◽  
X Ray ◽  
Hydrogen Bond System ◽  
Proton Disorder ◽  
Intramolecular Hydrogen ◽  
Carboxylic Acid Dimer

A new polymorph of 2,4-dihydroxybenzoic acid is reported. The structure was characterized by multiple-temperature X-ray diffraction and solid-state DFT computations. The material shows a geometric pattern of hydrogen bonding consistent with cooperativity between the intermolecular carboxylic acid dimer and intramolecular hydrogen bonds. The presence of proton disorder within this hydrogen-bond system, which would support such a cooperative model, was not fully ruled out by the initial X-ray studies. However, solid-state calculations on the three possible end-point tautomers indicate that the dominant crystallographically observed configuration is substantially lower in energy than the other tautomers (by at least 9 kJ mol−1), indicating that no disorder should be expected. It is therefore concluded that no disorder is observed either in the intra- or intermolecular hydrogen bonds of the title compound and that the cooperativity between the hydrogen bonds is not present within the temperature range studied.

The Hexakis(N,N'-Dimethylurea)Cobalt(Ii) Cation: A Flexible Building Block for the Construction of Hydrogen Bonded Networks

2003 ◽  
Vol 58 (1) ◽  
pp. 74-84 ◽  
Author(s):  
Giannis S. Papaefstathiou ◽  
Robby Keuleers ◽  
Constantinos J. Milios ◽  
Catherine P. Raptopoulou ◽  
Aris Terzis ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Solid State ◽  
Hydrogen Bonds ◽  
Spectroscopic Data ◽  
Low Frequency ◽  
Great Stability ◽  
Structure Determinations ◽  
Interionic Hydrogen ◽  
Hydrogen Bonded

AbstractThe ligand N.N'-dimethylurea (DMU) is used to propagate the octahedral coordination geom- etry of [Co(DMU)6]2+ into 1D and 2D assemblies via a combination of coordinative bonds and interionic hydrogen-bonding. Compounds [Co(DMU)6](ClO4)2 (1), [Co(DMU)6](BF4)2 (2) and [Co(DMU)6](NO3)2 (3) have been prepared from the reactions of DMU and the appropriate hydrated cobalt(II) salts in EtOH. MeCN or Me2CO (only for 1) in the presence of 2,2-di- methoxypropane. Crystal structure determinations demonstrate the existence of [Co(DMU)6]2+ cations and CIO4- , BF4- or NO3- counterions. The great stability of the [Co(DMU)6]2+ cation in the solid state is attributed to a pseudochelate effect which arises from the existence of strong intracationic N-H···O(DMU) hydrogen bonds. The [Co(DMU)6]2+ cations and counterions self- assemble to form a hydrogen-bonded ID architecture in 1, and different 2D hydrogen-bonded networks in 2 and 3. The precise nature of the resulting supramolecular structure is influenced by the nature of the counterion. Two main motifs of intermolecular (interionic) hydrogen bonds have been observed: N-H ···O(ClO4-, NO3-) or N-H ··· F(BF4-) and weak C-H F(BF4- ) or C-H-O(NO3- ) hydrogen bonds. The complexes were also characterized by vibrational spec- troscopy (IR, far-IR. low-frequency Raman). The spectroscopic data are discussed in terms of the nature of bonding and the know;n structures.

Spectroscopic studies of 2,6-dihydroxypyridine and some of its derivatives. Tautomerism in solution, and very strong hydrogen bonding in solid 2,6-dihydroxypyridine and its N-methylated derivative

1971 ◽  
Vol 24 (12) ◽  
pp. 2557 ◽  
Author(s):  
E Spinner ◽  
GB Yeoh
Keyword(s):  
Hydrogen Bonding ◽  
Solid State ◽  
Magnetic Resonance ◽  
Hydrogen Bonds ◽  
Proton Magnetic Resonance ◽  
Heavy Atom ◽  
Spectroscopic Studies ◽  
Macromolecular Structure ◽  
Present Evidence ◽  
Transmission Windows

Ultraviolet, infrared, and proton magnetic resonance spectra were measured for 2,6-dihydroxypyridine, 6-hydroxy-1-methylpyrid-2-one, α,α,γ-trichloro- and α,α,γ-tribromo-glutaconimide, with special reference to the hydroxypyridone-pyridinediol-glutaconimide equilibrium. The ratio [pyridol]/[pyridone] is much smaller for 2,6- dihydroxy-than for 6-methoxy-2-hydroxy-pyridine, especially in hydroxylic solvents. The hydroxypyridone form is the main or predominant tautomer for 2,6-dihydroxypyridine in water, dimethyl sulphoxide, ethanol, and 5% ethanol-95% cyclohexane, and for the 1- methylated derivative in ethanol. The glutaconimide form is the main or predominant tautomer for 2,6-dihydroxy-pyridine in dioxan, and for the 1-methylated derivative in water, dioxan, and chloroform. In the solid state 2,6-dihydroxypyridine and the 1-methylated derivative show a very broad intense infrared OH band with a plateau extending from c. 1300 cm-1 to, respectively, 800 and 450 cm-1, and with some transmission ?windows?; there is very strong hydrogen bonding, various aspects of which will be discussed. The solids probably consist of 6-hydroxypyrid- 2-one molecules linked by very short unsymmetrical hydrogen bonds; though, for the unmethylated compound, an alternative ?macromolecular? structure, consisting of units in which the heavy-atom skeletons have C2v symmetry, and are linked together by symmetrical hydrogen bonds, cannot be ruled out entirely on the present evidence.

Crystal Engineering of a New Layered Polyiodide Using 1,9-Diammoniononane as a Flexible Template Cation

2004 ◽  
Vol 59 (10) ◽  
pp. 1114-1117 ◽  
Author(s):  
Guido J. Reiß ◽  
Judith S. Engel
Keyword(s):  
Thermal Analysis ◽  
Hydrogen Bonding ◽  
Raman Spectrum ◽  
Solid State ◽  
Hydrogen Bonds ◽  
Crystal Engineering ◽  
Title Compound ◽  
State Structure ◽  
Cooperative Phenomenon ◽  
Weak Hydrogen Bonds

AbstractThe reaction of 1,9-diaminononane with hydroiodic acid in the presence of iodine gave a compound best described as 1,9-diammoniononane bis-triiodide iodine, (H3N-(CH2)9-NH3)[I3]2 · I2. The structure is built from two crystallographically independent I3− anions, which are connected via secondary I···I interactions to the iodine molecules, and the 1,9-diammonioalkane cations are connected via weak hydrogen bonds to neighbouring iodine atoms. By a cooperative phenomenon, the shape and the functionality of the cation lead to a solid state structure that includes a polyiodide substructure with the formula 2∞[I8]2− or 2∞[I3 · I2 · I3]2−, is best described as a brick-shaped layered array. Its rectangular pores fit excellently with the hydrogen bonding functionality as well as with the conformational needs of the 1,9-diammoniononane template. The Raman spectrum shows typical bands of coordinated triiodide anions and iodine molecules. The thermal analysis (DSC/TG) of the title compound indicates decomposition at temperatures above 210°C.

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