Hydrogen bonds and hydrogen-bonded systems in Mannich bases of 2,2′-biphenol: an FTIR study of the proton polarizability and Fermi resonance effects as a function of temperature

1995 ◽  
Vol 355 (2) ◽  
pp. 185-191 ◽  
Author(s):  
Bogumil Brzezinski ◽  
Piotr Radziejewski ◽  
Arno Rabold ◽  
Georg Zundel
Keyword(s):  
Hydrogen Bonds ◽  
Mannich Bases ◽  
Fermi Resonance ◽  
Resonance Effects ◽  
Ftir Study ◽  
Hydrogen Bonded Systems ◽  
Hydrogen Bonded

scholarly journals Theoretical Studies of Dynamic Interactions in Excited States of Hydrogen-Bonded Systems

2012 ◽  
Vol 2012 ◽  
pp. 1-17 ◽  
Author(s):  
Marek J. Wójcik ◽  
Marek Boczar ◽  
Łukasz Boda
Keyword(s):  
Hydrogen Bonds ◽  
Potential Energy ◽  
Benzoic Acid ◽  
Excited States ◽  
Potential Energy Surfaces ◽  
Low Frequency ◽  
Fermi Resonance ◽  
Tunneling Splittings ◽  
Energy Surfaces ◽  
Hydrogen Bonded

Theoretical model for vibrational interactions in the hydrogen-bonded benzoic acid dimer is presented. The model takes into account anharmonic-type couplings between the high-frequency O–H and the low-frequency O⋯O stretching vibrations in two hydrogen bonds, resonance interactions between two hydrogen bonds in the dimer, and Fermi resonance between the O–H stretching fundamental and the first overtone of the O–H in-plane bending vibrations. The model is used for theoretical simulation of the O–H stretching IR absorption bands of benzoic acid dimers in the gas phase in the first excited singlet state. Ab initio CIS and CIS(D)/CIS/6-311++G(d,p) calculations have been carried out in the à state of tropolone. The grids of potential energy surfaces along the coordinates of the tunneling vibration and the low-frequency coupled vibration have been calculated. Two-dimensional model potentials have been fitted to the calculated potential energy surfaces. The tunneling splittings for vibrationally excited states have been calculated and compared with the available experimental data. The model potential energy surfaces give good estimation of the tunneling splittings in the vibrationally ground and excited states of tropolone, and explain monotonic decrease in tunneling splittings with the excitation of low-frequency out-of-plane modes and increase of the tunneling splittings with the excitation of low-frequency planar modes.

Proton transfer in hydrogen bonded systems

1960 ◽  
Vol 257 (1288) ◽  
pp. 98-108 ◽  
Keyword(s):  
Hydrogen Bond ◽  
Absorption Band ◽  
Hydrogen Bonds ◽  
Proton Transfer ◽  
Direct Result ◽  
Isotopic Substitution ◽  
Association Energy ◽  
Hydrogen Bonded Systems ◽  
Hydrogen Bonded

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.

π-Bond cooperativity and anticooperativity effects in resonance-assisted hydrogen bonds (RAHBs)

2006 ◽  
Vol 62 (5) ◽  
pp. 850-863 ◽  
Author(s):  
Valerio Bertolasi ◽  
Loretta Pretto ◽  
Gastone Gilli ◽  
Paola Gilli
Keyword(s):  
Hydrogen Bonds ◽  
Local Defect ◽  
Bond Polarity ◽  
X Ray ◽  
Extensive Analysis ◽  
Cooperativity Effects ◽  
Structural Database ◽  
Hydrogen Bonded Systems ◽  
Hydrogen Bonded

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.

Fermi Resonance of Infrared Vibrations in the —NH2 Groups of Polynucleotides

1971 ◽  
Vol 49 (23) ◽  
pp. 3795-3798 ◽  
Author(s):  
G. Zundel ◽  
W. D. Lubos ◽  
K. Kölkenbeck
Keyword(s):  
Hydrogen Bonds ◽  
Harmonic Vibration ◽  
Fermi Resonance ◽  
Bending Vibration ◽  
Doublet Structure ◽  
Stretching Vibration ◽  
Stretching Vibrations ◽  
Band Pair ◽  
Hydrogen Bonded

The —NH2 group causes an intensive band pair in the i.r. spectra of DNA, r.RNA, poly (A + U), and poly (G + C). One band occurs at 3330, another at 3180 cm−1. This band pair is due to the NH stretching vibration of the hydrogen-bonded NH group as well as to the harmonic vibration of the —NH2 bending vibration, whereby these vibrations are coupled via Fermi resonance. This follows on comparison with papers on amines. The weak shoulder in the 3500–3400 cm−1 range is to be assigned to the stretching vibrations of the non hydrogen-bonded NH groups. The doublet structure disappears to a large extent in the denaturated DNA, since the strength of the Fermi resonance depends on the strength of the hydrogen bonds and the hydrogen bonds are of differing strength, due to the bending and stretching. The relative intensities of the two bands are interchanged in the corresponding band pair of the —ND2 groups, for which an explanation can also be given.

scholarly journals Combining Coordination and Hydrogen Bonds to Develop Discrete Supramolecular Metalla-Assemblies

Chemistry ◽  
2020 ◽  
Vol 2 (2) ◽  
pp. 565-576 ◽  
Author(s):  
Bruno Therrien
Keyword(s):  
Hydrogen Bonds ◽  
Metal Ions ◽  
Metal Coordination ◽  
Supramolecular Systems ◽  
Supramolecular Materials ◽  
Hydrogen Bonded Systems ◽  
Different Levels ◽  
Hydrogen Bonded

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.

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