The Influence of Pressure on the Infrared-Spectra of Hydrogen-Bonded Solids. VII. Deuterated Ammonium Salts

1988 ◽  
Vol 41 (12) ◽  
pp. 1935 ◽  
Author(s):  
SD Hamann
Keyword(s):  
Hydrogen Bonding ◽  
Infrared Spectra ◽  
Ammonium Salts ◽  
Ammonium Ions ◽  
Hydrogen Bonded

The infrared stretching and bending frequencies of isotopically dilute +NHD3 ions in predominantly +ND4 salts have been measured at pressures up to 5 GPa at 25°C. For most of the 28 salts studied, the stretching bands move to higher frequencies with increasing pressure, these results suggesting the absence of any significant hydrogen bonding between the ammonium ions and the anions in the crystals.

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 of Crystalline Acetic Acid, a Hydrogen-Bonded Polymer

1977 ◽  
Vol 31 (2) ◽  
pp. 110-115 ◽  
Author(s):  
P. F. Krause ◽  
J. E. Katon ◽  
J. M. Rogers ◽  
D. B. Phillips
Keyword(s):  
Hydrogen Bonding ◽  
Acetic Acid ◽  
Infrared Spectra ◽  
Group Analysis ◽  
Structural Models ◽  
Factor Group ◽  
Vibrational Modes ◽  
Cryogenic Temperatures ◽  
Polymeric Chains ◽  
Hydrogen Bonded

The polarized infrared spectra of crystalline acetic acid and two of its deuterated derivatives, CH3COOD and CD3COOD, have been recorded from 400 to 4000 cm−1 at cryogenic temperatures. The spectroscopic results have been interpreted on the basis of a factor group analysis based on two structural models: a crystallographic cell composed of four interacting monomer units some of whose vibrational modes are highly perturbed by hydrogen bonding and a unit cell composed of two noninteracting acetic acid chains. The results are discussed in terms of possible interactions between the hydrogen-bonded acetic acid polymeric chains.

H2O, HDO, and CH3OH Infrared Spectra and Correlation with Solvent Basicity and Hydrogen Bonding

1971 ◽  
Vol 49 (6) ◽  
pp. 837-856 ◽  
Author(s):  
D. N. Glew ◽  
N. S. Rath
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Infrared Spectra ◽  
Dibasic Acid ◽  
Tertiary Amines ◽  
Type Symmetry ◽  
Solvent Basicity ◽  
Organic Amines ◽  
Lower Frequencies ◽  
Hydrogen Bonded

A study has been made of the infrared O—H bands for CH3OH, DOH, and H2O in solution and of their correlation with hydrogen bonding and solvent basicity. Infrared bands for the three fundamentals and the first bending overtone of H2O and for the O—H stretching fundamentals of DOH and CH3OH have been measured between 30 and −40 °C in a solvent range extending from weakly interacting fluorocarbons to strongly hydrogen-bonding organic amines. The O—H stretching bands for the weakly acidic solutes CH3OH, DOH, and H2O are mostly Lorentzian in shape and move to lower frequencies with higher extinctions in the more basic solvents. Many correlations are found between the stretching frequencies and band areas, and between the frequencies and solvent basicity. Monofunctional CH3OH is found to be a stronger acid and forms stronger hydrogen-bonds with a given base than do the doubly bonded DOH and HOH which show equal dibasic acid strengths.The wide, overlapped, fundamental stretching bands for H2O strongly hydrogen-bonded to the tertiary amines and for ice have been partially resolved and unequivocally assigned, showing that there is no cross-over of the ν 3 and ν1 bands despite the strong hydrogen-bonding.At higher temperatures in solvents containing both hydrophobic and strongly basic groups water was found with the lower Cs type symmetry, in which unbonded O—H groups gave sharp bands in the 3680–3650 cm−1 region in addition to the wide hydrogen-bonded bands at lower frequencies.

Infrared spectra of the ammonium ion in crystals. Part XII. Low-temperature transitions in ammonium dichromate, (NH4)2Cr2O7

1982 ◽  
Vol 60 (15) ◽  
pp. 1972-1977
Author(s):  
Gábor Keresztury ◽  
Osvald Knop ◽  
Michael Falk
Keyword(s):  
Hydrogen Bonding ◽  
Infrared Spectra ◽  
Room Temperature ◽  
Abundance Ratio ◽  
Ammonium Ion ◽  
Ammonium Ions ◽  
Hydrogen Bonding Interactions ◽  
Wide Range ◽  
Ammonium Dichromate ◽  
The Difference

Examination of the infrared spectra of the probe ions NH3D+ and NHD3+ in ammonium dichromate confirms the existence of the lowest (Ttr ~ 125 K) of the three transitions that are known, from nonspectroscopic evidence, to occur in this crystal below room temperature. Below Ttr the ammonium ions are of two types, in an abundance ratio of 1:1 and both of symmetry C1. Above Ttr the probe ion spectra are difficult to interpret in detail. The strength of the hydrogen-bonding interactions covers a wide range, as indicated by the difference between the highest and the lowest values of the isotopically isolated ND stretching frequencies at 10 K, 2392 and 2234 cm−1.

scholarly journals Two-dimensional hydrogen-bonded polymers in the crystal structures of the ammonium salts of phenoxyacetic acid, (4-fluorophenoxy)acetic acid and (4-chloro-2-methylphenoxy)acetic acid

2014 ◽  
Vol 70 (12) ◽  
pp. 528-532 ◽  
Author(s):  
Graham Smith
Keyword(s):  
Hydrogen Bonding ◽  
Acetic Acid ◽  
Water Molecule ◽  
Rotation Axis ◽  
Ammonium Salts ◽  
Phenoxyacetic Acid ◽  
Two Dimensional ◽  
The Core ◽  
Ammonium N ◽  
Hydrogen Bonded

The structures of the ammonium salts of phenoxyacetic acid, NH4+·C8H6O3−, (I), (4-fluorophenoxy)acetic acid, NH4+·C8H5FO3−, (II), and the herbicidally active (4-chloro-2-methylphenoxy)acetic acid (MCPA), NH4+·C9H8ClO3−·0.5H2O, (III) have been determined. All have two-dimensional layered structures based on inter-species ammonium N—H...O hydrogen-bonding associations, which give core substructures consisting primarily of conjoined cyclic motifs. The crystals of (I) and (II) are isomorphous with the core comprisingR12(5),R12(4) and centrosymmetricR42(8) ring motifs, giving two-dimensional layers lying parallel to (100). In (III), the water molecule of solvation lies on a crystallographic twofold rotation axis and bridges two carboxyl O atoms in anR44(12) hydrogen-bonded motif, creating twoR43(10) rings, which together with a conjoined centrosymmetricR42(8) ring incorporating both ammonium cations, generate two-dimensional layers lying parallel to (100). No π–π ring associations are present in any of the structures.

The influence of pressure on the infrared spectra of hydrogen-bonded solids. VI. Ammonium salts

1978 ◽  
Vol 31 (1) ◽  
pp. 11 ◽  
Author(s):  
SD Hamann
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Infrared Spectra ◽  
Ammonium Salts ◽  
Bond Strengths ◽  
As If ◽  
Lower Frequencies ◽  
Hydrogen Bonded

The infrared spectra of 33 polycrystalline ammonium salts have been measured at 25°C, at pressures up to 45 kbar. The N-H stretching and bending bands of the hydrogen-bonded NH4+ ions of most of the salts shift anomalously to higher and to lower frequencies, respectively, as the pressure is raised. In this sense, the salts behave as if they had very strong hydrogen bonds, instead of quite weak ones. ��� A fairly good correlation exists between the N-H stretching frequencies of salts with N+-H...O bonds and their hydrogen bond strengths as measured by the minimum N+...O distances in their crystals.

Infrared Spectra of the Ammonium Ion in Crystals. II. The Ammonium Ion in Trigonal Environments, with a Consideration of Hydrogen Bonding

1975 ◽  
Vol 53 (22) ◽  
pp. 3394-3400 ◽  
Author(s):  
Ian A. Oxton ◽  
Osvald Knop ◽  
Michael Falk
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Infrared Spectra ◽  
Isotopic Dilution ◽  
Ammonium Ion ◽  
Ammonium Ions ◽  
Dilution Technique ◽  
Intensity Ratios ◽  
Normal Hydrogen ◽  
Trifurcated Hydrogen Bond

Infrared spectra of polycrystalline (NH4)2GeF6, β-(NH4)2SiF6, and (NH4)2Pb(SO4)2 have been recorded at room and liquid-nitrogen temperatures. The N—D stretching and bending fundamentals of the isotopically dilute NH3D+ ion in these compounds have been studied with particular attention. The occurrence of N—D stretching doublets and bending triplets, of approximate intensity ratios 1:3 and 2:3:3 respectively, confirms the C3v symmetry of the ammonium ion and suggests that the isotopic dilution technique will prove useful as a diagnostic tool for ascertaining site symmetries of the ammonium ion. The spectra are consistent with non-rotating ammonium ions. The frequencies of dilute NH3D+ ions suggest that for the ammonium ion in (NH4)2Pb(SO4)2 a trifurcated hydrogen bond is stronger than a normal hydrogen bond.

Infrared spectra of pyridine sorbed on porous glass

1968 ◽  
Vol 46 (20) ◽  
pp. 3255-3261 ◽  
Author(s):  
M. J. D. Low ◽  
V. V. Subba Rao
Keyword(s):  
Hydrogen Bonding ◽  
Nitrogen Atom ◽  
Infrared Spectra ◽  
Porous Glass ◽  
Physical Adsorption ◽  
Hydrogen Atoms ◽  
Oh Groups ◽  
Pure Silica ◽  
Hydrogen Bonded

Infrared spectra were recorded of pyridine (PY) sorbed on highly dehydroxylated, deuterated, and fluoridated porous glass, as well as on pure silica and boria-impregnated silica. The hydrogen atoms of sorbed PY exchange with surface OD groups. Physical adsorption occurs by hydrogen bonding of PY to SiOH and B—OH groups via the PY nitrogen atom; there is some interaction of the ring π system with OH groups. Surface B:PY complexes form by coordination of PY to boron; the B:PY may be hydrogen bonded to B—OH groups. Some PY dissociates, and OH groups are generated.

scholarly journals Resonanz-Raman-Effekt von Thiocyanatkomplexen einiger Übergangsmetalle

1970 ◽  
Vol 25 (10) ◽  
pp. 1394-1400 ◽  
Author(s):  
W. Krasser ◽  
H. W. Nürnberg
Keyword(s):  
Raman Spectrum ◽  
Infrared Spectra ◽  
High Intensity ◽  
High Frequency ◽  
Resonance Raman ◽  
Ammonium Salts ◽  
Iron Cobalt ◽  
Decay Products ◽  
Thiocyanate Complexes ◽  
Resonance Raman Spectra

Abstract The thiocyanates of the transition metals iron, cobalt, copper as well as of rhenium and of tech-netium appear in solution as strongly coloured complexes. The resonance raman bands in the sol-vent acetonitrile are investigated. To achieve an unambiguous identification the infrared spectra were recorded too. The change in position and structure of the acetonitrile bands indicates strong complexation of iron, cobalt and copper with acetonitrile, thus indicating the existence of mixed acetonitrile-thiocyanate complexes. The resonance raman spectra of the rhenium-and technetium-thiocyanates present as tetramethyl ammonium salts show however no raman-and infrared-bands of complexed acetonitrile molecules.In the raman spectrum of the thiocyanates of iron, cobalt and copper mainly the totally sym-metric C≡N, S-C, Me-S and Me-N valence vibrations are observed, among which the S-C vibration shows a remarkably high intensity. Besides, a series of bands is obtained which is inter-preted partly as caused by decay products, and partly as bands of complexed acetonitrile. The thiocyanates of rhenium and of technetium show the three possible valence vibrations only. The high frequency of the S-C valence indicates the N-coordination of the thiocyanate group.

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