THE INFRARED SPECTRA OF TRIMETHYLAMINE OXIDE SALTS

1963 ◽  
Vol 41 (5) ◽  
pp. 1127-1134 ◽  
Author(s):  
Denys Cook
Keyword(s):  
Hydrogen Bond ◽  
Infrared Spectra ◽  
Field Coupling ◽  
Correlation Field ◽  
Trimethylamine Oxide ◽  
Bending Mode ◽  
Good Agreement

Several salts of trimethylamine oxide have been prepared. A species common to all these salts, the (CH3)3NOH+ ion, has been inferred from the infrared spectra of the solids, but with varying degrees of interaction in the hydrogen bond [Formula: see text] depending on the anion. These variations have been investigated in detail, and with the help of deuterium replacement, confident assignments for the OH stretching, bending, and torsional modes have been made. A splitting of about 80 cm−1 in the bending mode has been noted, and has been ascribed to correlation field coupling. With one exception, the assignments are in good agreement with those previously determined by Giguère and Chin.

PROTONATED CARBONYL GROUPS: III. ANTIPYRINE SALTS

1963 ◽  
Vol 41 (11) ◽  
pp. 2794-2799 ◽  
Author(s):  
Denys Cook
Keyword(s):  
Hydrogen Atom ◽  
Hydrogen Bonds ◽  
Carbonyl Group ◽  
Infrared Spectra ◽  
Strong Absorption ◽  
Carbonyl Groups ◽  
Correlation Field ◽  
Bending Mode ◽  
Out Of Plane ◽  
Stretching Vibration

Salts of antipyrine (2,3-dimethyl-1-phenyl-5-pyrazolone) with halogen acids have been prepared and their infrared spectra from 4000 to 650 cm−1 recorded. Stoichiometrically they are normal 1:1 salts. Identification of bands due to vibrations of the protonating hydrogen atom has been aided by replacement with deuterium atoms. It is concluded that protonation occurs at the carbonyl group from the presence of a doublet (due to correlation field splitting) at 1320 and 1220 cm−1, attributed to the in-plane hydrogen-bending mode. The OH stretching vibration gives rise to bands between 2278 and 2720 cm−1 in the different salts. Out-of-plane hydrogen-bending mode absorptions are observed between 840 and 770 cm−1.More complex acids (HAsF6 etc.) give the anomalous 2 base:1 acid salts, characterized by strong absorption below 1400 cm−1, which probably contain strong, possibly symmetrical, hydrogen bonds.

PROTONATED CARBONYL GROUPS: IV. N,N-DIMETHYLACETAMIDE SALTS

1964 ◽  
Vol 42 (12) ◽  
pp. 2721-2727 ◽  
Author(s):  
Denys Cook
Keyword(s):  
Oxygen Atom ◽  
Infrared Spectra ◽  
Deformation Mode ◽  
Carbonyl Groups ◽  
Broad Absorption ◽  
Average Value ◽  
Correlation Field ◽  
Bending Mode ◽  
Out Of Plane ◽  
Transmission Windows

The infrared spectra of N,N-dimethylacelamide salts have been recorded and are consistent with protonation at the oxygen atom, vOH is between 2 095 and 3 360 cm−1 depending on the anion. The average value of the two components of the OH in-plane hydrogen-bending mode, δOH, is 1 253 cm−1 (splitting of about 147 cm−1 due to correlation field effects). The out-of-plane hydrogen-deformation mode occurs at 928 to 761 cm−1 depending on the salt. The 1 680 and 1 400 cm−1 bands which are present in all the salts are associated chiefly with stretching the CN and CO bonds respectively, in the OCN group, though it is likely that the vibrations are somewhat mixed.Some salts of complex acids are of the 2 base: 1 acid variety with very strong broad absorption centered near 900 cm−1, containing sharp transmission windows.

Far Infrared Group Frequencies. V. Oximes and Aldoximes

1973 ◽  
Vol 27 (1) ◽  
pp. 22-26 ◽  
Author(s):  
S. M. Craven ◽  
F. F. Bentley ◽  
D. F. Pensenstadler
Keyword(s):  
Hydrogen Bond ◽  
Infrared Spectra ◽  
Low Frequency ◽  
Far Infrared ◽  
Torsional Vibrations ◽  
Lattice Vibrations ◽  
Dilute Solutions ◽  
Solid Samples ◽  
Bending Modes ◽  
Bond Stretch

The low frequency infrared spectra from 450 to 75 cm−1 of seven oximes and five aldoximes have been recorded for pure samples and for dilute solutions in cyclohexane. An intense characteristic band is present in the solution spectra at 367 ± 10 cm−1. This characteristic band shifts to 275 ± 10 cm−1 in the spectra of the OD compounds. The 367 ± 10 cm−1 and 275 ± 10 cm−1 bands are assigned to OH and OD torsional vibrations. A comparison of the solution spectra with spectra of the solid samples indicated that the OH … N hydrogen bond stretch of oximes and aldoximes occurs in 300 to 200 cm−1 region. Strong bands also are present in 140 to 100 cm−1 region which are due to OH … N bending modes or perhaps lattice vibrations.

Infrared Spectra of Some Chloro Derivatives of s-Triazine

1966 ◽  
Vol 20 (3) ◽  
pp. 159-160 ◽  
Author(s):  
T. S. Herman
Keyword(s):  
Infrared Spectra ◽  
Triazine Ring ◽  
Chlorine Atoms ◽  
Vibrational Assignments ◽  
Fundamental Frequencies ◽  
Bending Mode ◽  
Chloro Derivatives ◽  
Derivatives Of

The effects of chlorine atoms on the fundamental frequencies of the s-triazine ring are discussed and the vibrational assignments in the region 1600–700 cm−1 are extended. The variation in the position of the C3N3-ring bending mode in the region near 810 cm−1 is discussed.

Contributions to Silicon-Hydrogen Bond-Stretching Frequency in Amorphous Si Alloys

1992 ◽  
Vol 258 ◽  
Author(s):  
Z. Jing ◽  
J. L. Whitten ◽  
G. Lucovsky
Keyword(s):  
Experimental Data ◽  
Hydrogen Bond ◽  
Dielectric Constant ◽  
Ab Initio ◽  
Effective Dielectric Constant ◽  
Bond Energies ◽  
Calculated Frequency ◽  
Bond Stretching ◽  
Amorphous Si ◽  
Good Agreement

ABSTRACTWe have performed ab initio calculations and determined the bond-energies and vibrational frequencies of Si-H groups that are: i) attached to Si-atoms as their immediate, and also more distant neighbors; and ii) attached to three O-atoms as their immediate neighbors, but are connected to an all Si-atom matrix. These arrangements simulate bonding geometries on Si surfaces, and the calculated frequency for i) is in good agreement with that of an Si-H group on an Si surface. To compare these results with a-Si:H alloys it is necessary to take into account an additional factor: the effective dielectric constant of the host. We show how to do this, demonstrating the way results of the ab initio calculations should then be compared with experimental data.

scholarly journals The Bending Mode of Water: A Powerful Probe for Hydrogen Bond Structure of Aqueous Systems

2020 ◽  
Vol 11 (19) ◽  
pp. 8459-8469
Author(s):  
Takakazu Seki ◽  
Kuo-Yang Chiang ◽  
Chun-Chieh Yu ◽  
Xiaoqing Yu ◽  
Masanari Okuno ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Aqueous Systems ◽  
Bending Mode

First-Principles Study of Structural and Vibrational Properties of α-SiO2 under Pressure

2015 ◽  
Vol 775 ◽  
pp. 191-196
Author(s):  
Xiao Wei Lei ◽  
Yong Song ◽  
Kuo Yang ◽  
Hui Zhao
Keyword(s):  
High Pressure ◽  
Perturbation Theory ◽  
Infrared Spectra ◽  
First Principles ◽  
Linear Response ◽  
Density Functional ◽  
Vibrational Properties ◽  
Vibrational Modes ◽  
Density Functional Perturbation Theory ◽  
Good Agreement

Using first principles approach, we present the structural, vibrational and dielectric properties of α-SiO2. The calculations have been carried out within the density functional perturbation theory and linear response formalism using the norm-concerving pseudopotentials and a plane wave basis. All the vibrational modes identified are in good agreement with experiment. The calculated infrared spectra are also in good agreement with available experimental results both for the positions and the intensities of the main peaks. We find that the modes Eu7 and A2u4 splits in two respectively at high hydrostaticpressures. Then we calculate the infrared spectra under high pressure of different orientations. The vibrational modes in different phase transitions are reported and discussed respectively.

The far-infrared spectra of arsenic chalcogenides

1971 ◽  
Vol 24 (4) ◽  
pp. 697 ◽  
Author(s):  
HJ Whitfield
Keyword(s):  
Infrared Spectra ◽  
Far Infrared ◽  
Symmetry Class ◽  
Strong Band ◽  
Bending Mode ◽  
Bending Modes ◽  
Far Infrared Spectra ◽  
Class E

The far-infrared spectra of AsS, As2S3, As4Se3, and As2Se3 are reported for the range 15-400 cm-1. For As4S3 molecules, of symmetry C3v, strong bands at 370 cm-1 and 340 cm-1 arise from symmetric As-S stretching frequencies of symmetry class A1 and a strong band at 176 cm-1 arises from a S-4s-S bending mode of degenerate class E. For As2Se3, bands in the region 90-130 cm-1 are identified as Se-As-Se bending modes and bands between 200 and 280 cm-1 are due to As-Se stretching modes.

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