IR continua of hydrogen bonds and hydrogen-bonded systems, calculated proton polarizabilities and line spectra

1989 ◽  
Vol 200 ◽  
pp. 73-92 ◽  
Author(s):  
Georg Zundel ◽  
Michael Eckert

Evidence is presented that proton transfer occurs in certain special types of hydrogen bond and that as a direct result the association energy is increased. It is probable that this effect is also responsible for a t least a part of the broadening of the v XH absorption band. In support of this, a number of com pounds are described in which the hydrogen bonds are weakened by isotopic substitution. The implications of these findings are discussed.


2006 ◽  
Vol 62 (5) ◽  
pp. 850-863 ◽  
Author(s):  
Valerio Bertolasi ◽  
Loretta Pretto ◽  
Gastone Gilli ◽  
Paola Gilli

Bond cooperativity effects, which are typical of `resonant' chains or rings of π-conjugated hydrocarbons, can also occur in hydrogen-bonded systems in the form of σ-bond and π-bond cooperativity or anticooperativity. σ-Bond cooperativity is associated with the long chains of O—H...O bonds in water and alcohols while σ-bond anticooperativity occurs when the cooperative chain is interrupted by a local defect reversing the bond polarity. π-Bond cooperativity is the driving force controlling resonance-assisted hydrogen bonds (RAHBs), while π-bond anticooperativity has never been considered so far and is investigated here by studying couples of hydrogen-bonded β-enolone and/or β-enaminone six-membered rings fused through a common C=O or C—C bond. The effect is studied by X-ray crystal structure determination of five compounds [(2Z)-1-(2-hydroxyphenyl)-3-phenyl-1,3-propanedione enol (1), (2Z)-1-(2-hydroxy-5-chlorophenyl)-3-phenyl-1,3-propanedione enol (2), (2Z)-1-(2-hydroxy-5-methylphenyl)-3-phenyl-1,3-propanedione enol (3), (2Z)-1-(2-hydroxy-4-methyl-5-chlorophenyl)-3-phenyl-1,3-propanedione enol (4) and dimethyl(2E)-3-hydroxy-2-{[(4-chlorophenyl)amino]carbonyl}pent-2-enedioate (5)] and by extensive analysis of related fragments found in the CSD (Cambridge Structural Database). It is shown that fusion through the C=O bond is always anticooperative and such to weaken the symmetric O—H...O...H—O and N—H...O...H—N bonds formed, but not the asymmetric O—H...O...H—N bond. Fusion through the C—C bond may produce either cooperative or anticooperative hydrogen bonds, the former being more stable than the latter and giving rise to a unique resonance-assisted ten-membered ring running all around the two fused six-membered rings, which can be considered a type of tautomerism never described before.


Chemistry ◽  
2020 ◽  
Vol 2 (2) ◽  
pp. 565-576 ◽  
Author(s):  
Bruno Therrien

In Nature, metal ions play critical roles at different levels, and they are often found in proteins. Therefore, metal ions are naturally incorporated in hydrogen-bonded systems. In addition, the combination of metal coordination and hydrogen bonds have been used extensively to develop supramolecular materials. However, despite this win-win combination between coordination and hydrogen bonds in many supramolecular systems, the same combination remains scarce in the field of coordination-driven self-assemblies. Indeed, as illustrated in this mini-review, only a few discrete supramolecular metalla-assemblies combining coordination and hydrogen bonds can be found in the literature, but that figure might change rapidly.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jichuan Zhang ◽  
Yongan Feng ◽  
Richard J. Staples ◽  
Jiaheng Zhang ◽  
Jean’ne M. Shreeve

AbstractOwing to its simple preparation and high oxygen content, nitroformate [−C(NO2)3, NF] is an extremely attractive oxidant component for propellants and explosives. However, the poor thermostability of NF-based derivatives has been an unconquerable barrier for more than 150 years, thus hindering its application. In this study, the first example of a nitrogen-rich hydrogen-bonded organic framework (HOF-NF) is designed and constructed through self-assembly in energetic materials, in which NF anions are trapped in pores of the resulting framework via the dual force of ionic and hydrogen bonds from the strengthened framework. These factors lead to the decomposition temperature of the resulting HOF-NF moiety being 200 °C, which exceeds the challenge of thermal stability over 180 °C for the first time among NF-based compounds. A large number of NF-based compounds with high stabilities and excellent properties can be designed and synthesized on the basis of this work.


Author(s):  
Yanqin Zhai ◽  
Peng Luo ◽  
Michihiro Nagao ◽  
Kenji Nakajima ◽  
Tatsuya Kikuchi ◽  
...  

2-propanol was investigated, in both the liquid and supercooled states, as a model system to study how hydrogen bonds affect the structural relaxation and the dynamics of mesoscale structures, of...


Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 926
Author(s):  
Malose J. Mphahlele ◽  
Eugene E. Onwu ◽  
Marole M. Maluleka

The conformations of the title compounds were determined in solution (NMR and UV-Vis spectroscopy) and in the solid state (FT-IR and XRD), complemented with density functional theory (DFT) in the gas phase. The nonequivalence of the amide protons of these compounds due to the hindered rotation of the C(O)–NH2 single bond resulted in two distinct resonances of different chemical shift values in the aromatic region of their 1H-NMR spectra. Intramolecular hydrogen bonding interactions between the carbonyl oxygen and the sulfonamide hydrogen atom were observed in the solution phase and solid state. XRD confirmed the ability of the amide moiety of this class of compounds to function as a hydrogen bond acceptor to form a six-membered hydrogen bonded ring and a donor simultaneously to form intermolecular hydrogen bonded complexes of the type N–H···O=S. The distorted tetrahedral geometry of the sulfur atom resulted in a deviation of the sulfonamide moiety from co-planarity of the anthranilamide scaffold, and this geometry enabled oxygen atoms to form hydrogen bonds in higher dimensions.


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