Infrared spectra of the ammonium ion in crystals. Part VI. Hydrogen bonding in simple and complex ammonium halides

1979 ◽  
Vol 57 (4) ◽  
pp. 404-423 ◽  
Author(s):  
Osvald Knop ◽  
Ian A. Oxton ◽  
Michael Falk
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Low Frequency ◽  
Volume Effect ◽  
Ammonium Ion ◽  
Ammonium Halides ◽  
Formal Charge ◽  
Two Factors ◽  
Frequency Branch ◽  
Free Ammonium

The ν1 and ν4bc infrared absorptions of the NH3D+ probe ion dispersed at low concentration in polycrystalline ammonium halides were used to investigate possible correlations between the frequencies of these absorptions and various structural and other parameters of the ammonium compounds. The most important among these parameters are the H … X distance, the acceptor strength of the halogen atom X for hydrogen bonding, and the coordination number C.N. and activation energy Ea for reorientation of the ammonium ion. It is found that the ν1 and ν4bc frequencies are affected by the acceptor strength and by the degree of 'compression' of the ammonium ion in the crystal, the volume effect. These two factors affect ν4bc in the same direction but ν1 in opposite directions. As a consequence, in a ν4bc vs. ν1 plot the halides are separated according to X, C.N., and certain other parameters. The effective radius of the ammonium ion in cubic (NH4)2MX6 is shown to increase with the strength of hydrogen bonding.The Ea vs ν1 plot contains two branches. The low-frequency branch is dominated principally by the strength of the hydrogen bonding and corresponds to C.N. 4 and 8 and to normal hydrogen bonds. The high-frequency branch is dominated principally by the volume effect and corresponds to C.N. 12 and to hydrogen bonds of highly dynamic character (fluxional hydrogen bonds). Ammonium ions with C.N. 6 may correspond to either branch, depending on the formal charge on X. Existence of the so-called symmetrically trifurcated hydrogen bond that has been proposed for the ammonium ion in certain coordinations is not supported by the present evidence.The problem of the fundamental vibrational frequencies of the 'free' ammonium ion is discussed and values are proposed for the 'limiting' ν1. and ν4bc frequencies in ammonium halides. Criteria of hydrogen bonding in ammonium halides are reviewed and comment is offered on symmetry aspects of crystallographic transformations in cubic hexahalometallates(IV), A2MX6.

Infrared spectra of the ammonium ion in crystals. Part VI. Hydrogen bonding in simple and complex ammonium halides

1979 ◽  
Vol 57 (15) ◽  
pp. 2003-2003
Author(s):  
Osvald Knop ◽  
Ian A. Oxton ◽  
Michael Falk
Keyword(s):  
Hydrogen Bonding ◽  
Infrared Spectra ◽  
Ammonium Ion ◽  
Ammonium Halides

not available

The Hexakis(N,N'-Dimethylurea)Cobalt(Ii) Cation: A Flexible Building Block for the Construction of Hydrogen Bonded Networks

2003 ◽  
Vol 58 (1) ◽  
pp. 74-84 ◽  
Author(s):  
Giannis S. Papaefstathiou ◽  
Robby Keuleers ◽  
Constantinos J. Milios ◽  
Catherine P. Raptopoulou ◽  
Aris Terzis ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Solid State ◽  
Hydrogen Bonds ◽  
Spectroscopic Data ◽  
Low Frequency ◽  
Great Stability ◽  
Structure Determinations ◽  
Interionic Hydrogen ◽  
Hydrogen Bonded

AbstractThe ligand N.N'-dimethylurea (DMU) is used to propagate the octahedral coordination geom- etry of [Co(DMU)6]2+ into 1D and 2D assemblies via a combination of coordinative bonds and interionic hydrogen-bonding. Compounds [Co(DMU)6](ClO4)2 (1), [Co(DMU)6](BF4)2 (2) and [Co(DMU)6](NO3)2 (3) have been prepared from the reactions of DMU and the appropriate hydrated cobalt(II) salts in EtOH. MeCN or Me2CO (only for 1) in the presence of 2,2-di- methoxypropane. Crystal structure determinations demonstrate the existence of [Co(DMU)6]2+ cations and CIO4- , BF4- or NO3- counterions. The great stability of the [Co(DMU)6]2+ cation in the solid state is attributed to a pseudochelate effect which arises from the existence of strong intracationic N-H···O(DMU) hydrogen bonds. The [Co(DMU)6]2+ cations and counterions self- assemble to form a hydrogen-bonded ID architecture in 1, and different 2D hydrogen-bonded networks in 2 and 3. The precise nature of the resulting supramolecular structure is influenced by the nature of the counterion. Two main motifs of intermolecular (interionic) hydrogen bonds have been observed: N-H ···O(ClO4-, NO3-) or N-H ··· F(BF4-) and weak C-H F(BF4- ) or C-H-O(NO3- ) hydrogen bonds. The complexes were also characterized by vibrational spec- troscopy (IR, far-IR. low-frequency Raman). The spectroscopic data are discussed in terms of the nature of bonding and the know;n structures.

Past Results and Future Prospects of the Far-Infrared Studies of Hydrogen Bonding

1968 ◽  
Vol 22 (6) ◽  
pp. 641-649 ◽  
Author(s):  
R. J. Jakobsen ◽  
J. W. Brasch ◽  
Y. Mikawa
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Low Frequency ◽  
Far Infrared ◽  
Future Prospects ◽  
The Past ◽  
Ir Studies ◽  
Infrared Studies ◽  
Order Of Magnitude

In the past five years the number of papers concerned with far-ir studies of hydrogen bonding has increased by an order of magnitude. The results of some of these papers are presented in this review. Most of this work is concerned with the assignment of low frequency hydrogen bond vibrations. Since the major problem is reliable assignments, we discuss techniques used in making the assignments and emphasize the past work in which attempts have been made to substantiate those assignments. These assignments are discussed in terms of the different hydrogen bond vibrations associated with various types of hydrogen bonds. The main needs for future far ir hydrogen bond studies are listed.

scholarly journals Hydrogen Bonds: Raman Spectroscopic Study

2021 ◽  
Vol 22 (10) ◽  
pp. 5380
Author(s):  
Boris A. Kolesov
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Spectroscopic Study ◽  
Raman Spectra ◽  
Temperature Region ◽  
Vibrational Frequency ◽  
Chemical Compounds ◽  
Raman Spectroscopic ◽  
Raman Spectroscopic Study ◽  
Proton Dynamics

The work outlines general ideas on how the frequency and the intensity of proton vibrations of X–H×××Y hydrogen bonding are formed as the bond evolves from weak to maximally strong bonding. For this purpose, the Raman spectra of different chemical compounds with moderate, strong, and extremely strong hydrogen bonds were obtained in the temperature region of 5 K–300 K. The dependence of the proton vibrational frequency is schematically presented as a function of the rigidity of O-H×××O bonding. The problems of proton dynamics on tautomeric O–H···O bonds are considered. A brief description of the N–H···O and C–H···Y hydrogen bonds is given.

Infrared spectra of the ammonium ion in crystals. Part VIII. Spectroscopic criteria of highly-bent hydrogen bonds

1980 ◽  
Vol 58 (9) ◽  
pp. 867-874 ◽  
Author(s):  
Osvald Knop ◽  
Wolfgang J. Westerhaus ◽  
Michael Falk
Keyword(s):  
Low Temperature ◽  
Hydrogen Bonds ◽  
Infrared Spectra ◽  
Room Temperature ◽  
Ammonium Ion ◽  
Temperature Transition ◽  
Increasing Temperature

Available evidence suggests that (1) the stretching frequencies of highly-bent hydrogen bonds decrease with increasing temperature, regardless of whether the bonds are static or dynamic in character, to a single acceptor or to several competing acceptors; and (2) departures from symmetric trifurcation (or bifurcation) toward asymmetric situations lower the stretching frequency. In further support of these criteria isotopic probe ion spectra between 10 K and room temperature have been obtained for taurine and for trigonal (NH4)2MF6 (M = Si, Ge, Sn, Ti). Evidence of a low-temperature transition at 100(10) K in trigonal (NH4)2SnF6 is presented, and existence of the previously reported transition at 38.6 K in trigonal (NH4)2SiF6 is confirmed. Symmetry changes associated with these transitions are discussed.

2-Hydroxy-3-methoxybenzaldehyde (pyridinium-4-ylcarbonyl)hydrazone chloride hemihydrate

2006 ◽  
Vol 62 (5) ◽  
pp. o2043-o2044 ◽  
Author(s):  
Shao-Wen Chen ◽  
Han-Dong Yin ◽  
Da-Qi Wang ◽  
Xia Kong ◽  
Xiao-Fang Chen
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Compound C

The crystal structure of the title compound, C14H14ClN3O3 +·Cl−·0.5H2O, exhibits O—H...O, C—H...O, C—H...Cl, N—H...Cl and O—H...Cl hydrogen bonds. The chloride anions participate in extensive hydrogen bonding with the aminium cations and link molecules through multiple N—H+...Cl− interactions.

Five pseudopolymorphs of 6-amino-2-thiouracil: absence of N—H...S hydrogen bonds

2012 ◽  
Vol 69 (1) ◽  
pp. 93-100 ◽  
Author(s):  
Wilhelm Maximilian Hützler ◽  
Michael Bolte
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Cambridge Structural Database ◽  
Hydrogen Bonding Pattern ◽  
Crystallization Experiments ◽  
Structural Database ◽  
Thiouracil Derivatives

In order to study the preferred hydrogen-bonding pattern of 6-amino-2-thiouracil, C4H5N3OS, (I), crystallization experiments yielded five different pseudopolymorphs of (I), namely the dimethylformamide disolvate, C4H5N3OS·2C3H7NO, (Ia), the dimethylacetamide monosolvate, C4H5N3OS·C4H9NO, (Ib), the dimethylacetamide sesquisolvate, C4H5N3OS·1.5C4H9NO, (Ic), and two different 1-methylpyrrolidin-2-one sesquisolvates, C4H5N3OS·1.5C5H9NO, (Id) and (Ie). All structures containR21(6) N—H...O hydrogen-bond motifs. In the latter four structures, additionalR22(8) N—H...O hydrogen-bond motifs are present stabilizing homodimers of (I). No type of hydrogen bond other than N—H...O is observed. According to a search of the Cambridge Structural Database, most 2-thiouracil derivatives form homodimers stabilized by anR22(8) hydrogen-bonding pattern, with (i) only N—H...O, (ii) only N—H...S or (iii) alternating pairs of N—H...O and N—H...S hydrogen bonds.

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