scholarly journals Weak hydrogen bonding motifs of ethylamino neurotransmitter radical cations in a hydrophobic environment: infrared spectra of tryptamine+–(N2)n clusters (n ≤ 6)

2014 ◽  
Vol 16 (8) ◽  
pp. 3798 ◽  
Author(s):  
Kenji Sakota ◽  
Markus Schütz ◽  
Matthias Schmies ◽  
Raphael Moritz ◽  
Aude Bouchet ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Infrared Spectra ◽  
Radical Cations ◽  
Weak Hydrogen Bonding

scholarly journals Effects of alkanolamine solvents on the aggregation states of reactive dyes in concentrated solutions and the properties of the solutions

RSC Advances ◽  
2021 ◽  
Vol 11 (18) ◽  
pp. 10929-10934
Author(s):  
Chuangui Cao ◽  
Zhihui Zhao ◽  
Yong Qi ◽  
Hui Peng ◽  
Kuanjun Fang ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Steric Hindrance ◽  
Reactive Dyes ◽  
Concentrated Solutions ◽  
Weak Hydrogen Bonding ◽  
Dye Aggregation

The solvent, DEA, reduces the dye aggregation that may be caused by the weak hydrogen bonding and relatively smaller steric hindrance effect.

scholarly journals Theoretical Study of the Structures of 4-(2,3,5,6-Tetrafluoropyridyl)Diphenylphosphine Oxide and Tris(Pentafluorophenyl)Phosphine Oxide: Why Does the Crystal Structure of (Tetrafluoropyridyl)Diphenylphosphine Oxide Have Two Different P=O Bond Lengths?

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2778
Author(s):  
Joseph R. Lane ◽  
Graham C. Saunders
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Phosphine Oxide ◽  
Density Functional ◽  
Lone Pair ◽  
Diphenylphosphine Oxide ◽  
Functional Theory ◽  
Weak Hydrogen Bonding ◽  
Independent Molecules ◽  
The Difference

The crystal structure of 4-(2,3,5,6-tetrafluoropyridyl)diphenylphosphine oxide (1) contains two independent molecules in the asymmetric unit. Although the molecules are virtually identical in all other aspects, the P=O bond distances differ by ca. 0.02 Å. In contrast, although tris(pentafluorophenyl)phosphine oxide (2) has a similar crystal structure, the P=O bond distances of the two independent molecules are identical. To investigate the reason for the difference, a density functional theory study was undertaken. Both structures comprise chains of molecules. The attraction between molecules of 1, which comprises lone pair–π, weak hydrogen bonding and C–H∙∙∙arene interactions, has energies of 70 and 71 kJ mol−1. The attraction between molecules of 2 comprises two lone pair–π interactions, and has energies of 99 and 100 kJ mol−1. There is weak hydrogen bonding between molecules of adjacent chains involving the oxygen atom of 1. For one molecule, this interaction is with a symmetry independent molecule, whereas for the other, it also occurs with a symmetry related molecule. This provides a reason for the difference in P=O distance. This interaction is not possible for 2, and so there is no difference between the P=O distances of 2.

Self-assembly of 2,6-dimethylpyridine on Cu(110) directed by weak hydrogen bonding

2007 ◽  
Vol 601 (16) ◽  
pp. L91-L94 ◽  
Author(s):  
Junseok Lee ◽  
Daniel B. Dougherty ◽  
John T. Yates
Keyword(s):  
Hydrogen Bonding ◽  
Self Assembly ◽  
Weak Hydrogen Bonding

Hydrogen bonding and conformation in cis- and trans-2-alkoxy-3-hydroxytetrahydrofurans

1968 ◽  
Vol 46 (1) ◽  
pp. 21-24 ◽  
Author(s):  
W. W. Zajac Jr. ◽  
F. Sweet ◽  
R. K. Brown
Keyword(s):  
Hydrogen Bonding ◽  
Infrared Spectra ◽  
Hydroxyl Absorption ◽  
Cis And Trans ◽  
In Cis ◽  
Infrared Data ◽  
Hydrogen Bonded

Infrared spectra show both free and hydrogen bonded hydroxyl absorption in several trans-2-alkoxy-3-hydroxytetrahydrofurans. The extent of non-bonded hydroxyl is greater than that of bonded hydroxyl. Suggestions are made of possible conformations which might account for the infrared data.

Infrared spectra and hydrogen bonding of pentitols and pyranosides at 20 to 300 K

2000 ◽  
Vol 328 (3) ◽  
pp. 307-319 ◽  
Author(s):  
Mark Rozenberg ◽  
Aharon Loewenschuss ◽  
Yizhak Marcus
Keyword(s):  
Hydrogen Bonding ◽  
Infrared Spectra

Degradation of Cytosine Radical Cations in 2′-Deoxycytidine and in i-Motif DNA: Hydrogen-Bonding Guided Pathways

2019 ◽  
Vol 141 (5) ◽  
pp. 1970-1979 ◽  
Author(s):  
Yinghui Wang ◽  
Hongmei Zhao ◽  
Chunfan Yang ◽  
Jialong Jie ◽  
Xiaojuan Dai ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Radical Cations

Hydrogen bonding in the gas phase: the thermodynamic properties of hydrogen fluoride-ether complexes and their far infrared spectra

1971 ◽  
Vol 322 (1548) ◽  
pp. 137-146 ◽  
Keyword(s):  
Hydrogen Bonding ◽  
Gas Phase ◽  
Infrared Spectra ◽  
Equilibrium Constants ◽  
Far Infrared ◽  
Methyl Ethyl ◽  
Rotational Contour ◽  
Stretching Vibration ◽  
Conformational Rearrangements ◽  
Far Infrared Spectra

The equilibrium constants of gas-phase complexes of HF with dimethyl, methyl ethyl and diethyl ether have been measured at several temperatures using the Benesi-Hildebrand approximation on the absorption band of the HF stretching vibration in the complex. From these, values of Δ H of — 43, — 38 and — 30 kJ mol -1 respectively, have been determined. They are interpreted in terms of conformational rearrangements of the ethers when they form hydrogen bonds. The far infrared spectra of the complexes with both HF and DF have also been recorded and in each case a band observed at around 180 cm -1 which is assigned to the intermolecular stretching mode of vibration. For the complex between HF and dimethyl ether a rotational contour has been observed at about 10 cm -1 .

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