Infrared studies of water in crystalline hydrates: NaClO4•H2O, LiClO4•3H2O, and Ba(ClO4)2•3H2O

1970 ◽  
Vol 48 (13) ◽  
pp. 2096-2103 ◽  
Author(s):  
George Brink ◽  
Michael Falk
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Atom ◽  
Room Temperature ◽  
Water Molecules ◽  
Weak Hydrogen Bond ◽  
Kcal Mole ◽  
Hydrogen Bond Energy ◽  
Weak Hydrogen Bonds ◽  
Infrared Studies ◽  
Crystalline Hydrates

Infrared spectra of undeuterated and partially deuterated NaclO4•H2O, LiClO4•3H2O, and Ba(ClO4)2•3H2O were examined. Crystallographic data point to a weak hydrogen bond between water molecules and the perchlorate ions in LiClO•3H2O. This is confirmed by the high HDO stretching frequencies for this compound. The nearly identical HDO stretching frequencies in LiClO4•3H2O, NaClO4•H2O, Ba(ClO4)2•3H2O, and in aqueous solutions of these salts show that similar weak hydrogen bonds occur in all three hydrates and in solution. The hydrogen bond energy is of the order of 2 kcal/mole. In all three compounds the water molecules are symmetric at room temperature. At −165° the water molecules become highly distorted in the sodium compound, slightly distorted in the barium compound, and remain undistorted in the lithium compound. Very narrow OD stretching bands are observed, showing that the hydrogen atom positions are ordered in all three hydrates.

Infrared studies of water in crystalline hydrates: K2HgCl4.H2O

1977 ◽  
Vol 55 (10) ◽  
pp. 1736-1744 ◽  
Author(s):  
Michael Falk ◽  
Osvald Knop
Keyword(s):  
Hydrogen Bond ◽  
Neutron Diffraction ◽  
Bond Distance ◽  
Single Type ◽  
Water Molecules ◽  
Dynamic Coupling ◽  
X Ray ◽  
Hydrogen Bond Distance ◽  
Infrared Studies ◽  
Crystalline Hydrates

Infrared spectra of polycrystalline K2HgCl4.H2O at different degrees of deuteration were recorded, in the 4000–250 cm−1 region, at temperatures between liquid-nitrogen and 130 °C. The spectra confirm the existence of a single type of water molecule, engaged in two equivalent hydrogen bonds. The value of 2548 cm−1 for the isolated O—D stretching frequency leads to an estimate of 3.25(3) Å for the O … Cl hydrogen-bond distance, in excellent agreement with the results of X-ray and neutron diffraction. Dynamic coupling is appreciable for stretch, bend, and librational fundamentals but is weaker than in CuCl2.2H2O or K2CuCl4.2H2O, in which the water molecules in the crystal are more tightly bonded.A number of corrected values are reported of isolated O—D stretching frequencies in hydrates studied previously.

Infrared Studies of Water in Crystalline Hydrates: LiI.3H2O

1971 ◽  
Vol 49 (3) ◽  
pp. 347-351 ◽  
Author(s):  
George Brink ◽  
Michael Falk
Keyword(s):  
Hydrogen Bond ◽  
Water Molecule ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Infrared Studies ◽  
Librational Motion ◽  
Increasing Temperature ◽  
Crystalline Hydrates

The infrared spectra of undeuterated and partially deuterated LiI.3H2O were recorded between 4000 and 1000 cm−1. The splitting of the fundamentals of isotopically dilute HDO indicates that the water molecules are distorted and form one strong, linear OH … I− hydrogen bond and one weak, non-linear hydrogen bond. The non-equivalence of the two hydrogens of the water molecule disagrees with the space group P63mc − C6υ4 for this hydrate, proposed on the basis of X-ray diffraction studies. It is concluded that the space group, including hydrogens, is one of lower symmetry, P63 − C66. The gradual broadening and convergence of the HDO fundamentals at increasing temperature is explained by increasing librational motion of the water molecules.

scholarly journals INFRARED SPECTRA OF THIOSACCHARINATES OF CADMIUM AND LEAD COMPARISON WITH THE ANALOGOUS METAL SACCHARINATES

2017 ◽  
Vol 27 (1-2) ◽  
Author(s):  
Gligor Jovanovski ◽  
Adnan Kahil ◽  
Orhideja Grupče
Keyword(s):  
Infrared Spectra ◽  
Room Temperature ◽  
Spectral Characteristics ◽  
Crystalline Hydrate ◽  
Water Molecules ◽  
X Ray ◽  
Weak Hydrogen Bonds ◽  
Deuterated Analogue ◽  
The Fourier Transform ◽  
Cadmium And Lead

A b s t r a c t: The Fourier transform (FT) infrared spectra of thiosaccharinates of cadmium and lead in the 4000–400 cm–1 region were studied. Although the observed resemblance between the spectra recorded in KBr pellets suggests a possible similarity between their structures as well, the powder X-ray diagrams show that these two compounds are not isomorphous. The presence of broad and intense bands in the region of the HOH stretchings shows that thiosaccharinate of cadmium is a crystalline hydrate and the spectral picture in the region of the O-D stretchings of the isotopically isolated HOD molecules in the partially deuterated analogue indicates that present in its structure are at least two types of crystallographically different water molecules involved in the formation of weak hydrogen bonds. The room temperature (RT) spectrum of lead thiosaccharinate in the region of the ν(HOH) modes differs significantly from the spectrum recorded at the boiling temperature of liquid nitrogen (LNT), which may perhaps be interpreted as an indication that a phase transition is taking place on lowering the temperature. The spectrum of lead thiosaccharinate was recorded in a Nujol mull as well. While the KBr and Nujol spectra are essentially identical in the region below 1600 cm–1, no bands are observed in the HOH stretching region of the mull spectra. In fact, it was shown that the appearance of the spectra of lead thiosaccharinates depends on the emulsion preparation rate. A comparison of the spectral characteristics of the thiosaccharinates of cadmium and lead with those of the corresponding saccharinates (their crystal structures are known) was made, special attention being paid to the analysis of the SO2 stretching region in the saccharinate and thiosaccharinate compounds.

scholarly journals Hydrogen Bond Studies. 125. A Deuteron Magnetic Resonance Study of Strontium Formate Dihydrate, Sr(HCOO)2 · 2D2O

1977 ◽  
Vol 32 (9) ◽  
pp. 1025-1029 ◽  
Author(s):  
Bo Berglund ◽  
Jörgen Tegenfeldt
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Magnetic Resonance ◽  
Electric Field Gradient ◽  
Room Temperature ◽  
Coupling Constants ◽  
Water Molecules ◽  
Magnetic Resonance Study ◽  
Quadrupole Coupling ◽  
Asymmetry Parameters

AbstractA room temperature (25 °C) deuteron magnetic resonance (DMR) study of a single crystal of Sr (HCOO)2 · 2 D2O is reported. Signals from all water molecules in the unit cell have been detected, and all four independent electric field gradient (EFG) tensors at the water deuterons have been determined from 409 quadrupole splittings. All spectra were recorded by rotating the crystal about one arbitrarily selected axis. The following quadrupole coupling constants and asymmetry parameters for the deuterons were obtained: 213.5(4), 189.3(4), 195.7(4) and 200.7(5) kHz and 0.117(3), 0.110(4), 0.116(4) and 0.098(3). The directions of the eigenvalues are qualitatively consistent with the crystal structure refined by Galigné 1; the result is in disagreement, however, with the earlier DMR study of Sr (DCOO)2 · 2 D2O (Reference 2).

Infrared Studies of Water in Crystalline Hydrates: Sodium Nitroprusside Dihydrate, Na2[Fe(CN)5NO]•2H2O

1971 ◽  
Vol 49 (9) ◽  
pp. 1413-1424 ◽  
Author(s):  
Michaela Holzbecher ◽  
Osvald Knop ◽  
Michael Falk
Keyword(s):  
Water Molecule ◽  
Sodium Nitroprusside ◽  
Infrared Spectra ◽  
Structure Determination ◽  
The Other ◽  
Water Molecules ◽  
Infrared Studies ◽  
Increasing Temperature ◽  
Crystalline Hydrates ◽  
The Ideal

Infrared spectra of polycrystalline Na2[Fe(CN)5NO] 2H2O at different degrees of deuteration were studied as a function of temperature. The single peaks observed for the bending fundamentals of isotopically dilute H2O and D2O show that all the water molecules are equivalent, as required by Manoharan and Hamilton's structure determination; the doublets observed for the three fundamentals of isotopically dilute HDO show that the water molecules are asymmetric. Doublet separation decreases gradually with increasing temperature, indicating decreasing asymmetry. The water molecule appears to orient itself so as to maximize the strength of one [Formula: see text] bond, while the other OH group interacts only very weakly with another CN group. The hitherto unknown extent to which the nitroprusside ion deviates from the ideal C4v symmetry has been estimated from the 13C14N stretching spectrum. The 15N16O and 14N18O stretching spectrum was used to confirm that only one type of NO group is present in the crystal, and hence that all nitroprusside ions are equivalent.

The infra-red spectra of talc, saponite, and hectorite

1958 ◽  
Vol 31 (241) ◽  
pp. 829-845 ◽  
Author(s):  
V. C. Farmer
Keyword(s):  
Hydrogen Bond ◽  
Dipole Moment ◽  
Absorption Spectra ◽  
Water Molecules ◽  
Weak Hydrogen Bond ◽  
Interlayer Water ◽  
Spectral Changes ◽  
Infra Red ◽  
Theoretical Predictions ◽  
Stretching Vibrations

SummaryThe absorption spectra of talc, saponite, and hectorite between 4000 and 400 cm. −1 are closely related, although the bands of the smectites are more diffuse as a result of isomorphous substitutions in the tale structure. Using oriented specimens, vibrations in which the change of dipole moment is perpendicular to the sheets of the minerals are identified, and the results compared with theoretical predictions. Three bands arising from the stretching vibrations of interlayer water molecules in the smectites are distinguished, one of which corresponds to a very weak hydrogen bond. Spectral changes arising from vigorous grinding are discussed.

The crystal structure of the complex salt: benzimidazole benzimidazolium fluoroborate

1976 ◽  
Vol 54 (15) ◽  
pp. 2482-2487 ◽  
Author(s):  
Andrew Quick ◽  
David J. Williams
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Atom ◽  
Least Squares ◽  
Room Temperature ◽  
Three Dimensional ◽  
Complex Salt ◽  
Bond Lengths ◽  
Block Diagonal

The crystal structure of benzimidazole benzimidazolium fluoroborate has been determined at room temperature from three-dimensional diffractometer data, and refined by block-diagonal least-squares to a final R = 0.050. The planar benzimidazole rings are inclined at 7.6° to each other and linked by a hydrogen bond of 2.787(3) Å with the proton in an asymmetric single minimum. The asymmetric siting of the hydrogen atom has produced characterising effects on the bond lengths and angles of the ring to which it is attached.

scholarly journals A Novel One-Dimensional Copper Mellitate Complex Featured by {Cu(H2O)2(urea)[C6(COO)4(COOH)2]}n 2n- Polyanions

2019 ◽  
Author(s):  
Roberto Köferstein
Keyword(s):  
Aqueous Solution ◽  
Coordination Polymer ◽  
Oxygen Atom ◽  
Room Temperature ◽  
Water Molecules ◽  
The Novel ◽  
One Dimensional ◽  
Thermoanalytical Investigations ◽  
Decomposition Processes ◽  
Weak Hydrogen Bonds

Blue monoclinic single crystals of the novel one-dimensional [H3N-(CH2)6-NH3][Cu(H2O)2(urea)(μ2-C6(COO)4 (COOH)2)]H2O coordination polymer have beenprepared in aqueous solution at room temperature in the presence of 1,6-diaminohexane andurea. Space group P21/n (no. 14) with a = 958.48(9), b = 1465.74(11), c = 1821.14(12) pm, beta= 97.655(8)°. The Cu2+ cation is coordinated in a square pyramidal manner by two oxygen atoms stemming from the dihydrogen mellitate tetraanion, one oxygen atom from the ureamolecule, and two water molecules. The Cu−O distances are between 193.3(2) and 229.4(2)pm. The connection between Cu2+ and [C6(COO)4(COOH)2]4 yields infinite chain-likepolyanions parallel to [ 01] with a composition of{Cu(H2O)2(urea)[C6(COO)4(COOH)2]}n2n-. The dihydrogen mellitate tetraanion adopts a μ2coordination mode. The [(H3N-(CH2)6-NH3)]2+ cations are accommodated between the chainsas counter cations. The hexane-1,6-diammonium cations adopt a partial synclinal conformation. The chains are connected by strong and weak hydrogen bonds. Magneticmeasurements reveal a paramagnetic Curie-Weiss behaviour and a magnetic moment of 1.93μB per Cu2+. Thermoanalytical investigations in air show that the complex is stable up to 135°C. Following decomposition processes yielding CuO.

Infrared Spectra of Water in Crystalline Hydrates: KSnCl3•H2O, an Untypical Monohydrate

1974 ◽  
Vol 52 (16) ◽  
pp. 2928-2931 ◽  
Author(s):  
Michael Falk ◽  
Chung-Hsi Huang ◽  
Osvald Knop
Keyword(s):  
Hydrogen Bonds ◽  
Infrared Spectra ◽  
Low Temperatures ◽  
Room Temperature ◽  
Water Molecules ◽  
Crystalline Hydrates

Infrared spectra of polycrystalline KSnCl3•H2O were recorded between 4000 and 300 cm−1 at different degrees of deuteration and at temperatures between 30 and −160 °C. At low temperatures the spectra show a complexity indicative of the presence of several crystallographically distinct water molecules. These molecules occupy sites with nearly identical environments and at room temperature are spectroscopically indistinguishable. The environment of each of these molecules is asymmetric. Hydrogen bonds are very weak and probably highly bent. The water molecules are less separated from one another than in K2SnCl4•H2O and may share their potassium neighbors.

MmHn(XO4)(m+n)/2crystals: structure, phase transitions, hydrogen bonds, conductivity. I. K9H7(SO4)8·H2O crystals – a new representative of the family of solid acid conductors

2014 ◽  
Vol 70 (2) ◽  
pp. 218-226 ◽  
Author(s):  
Irina Makarova ◽  
Vadim Grebenev ◽  
Elena Dmitricheva ◽  
Valentina Dolbinina ◽  
Dmitry Chernyshov
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Room Temperature ◽  
Water Molecules ◽  
Outward Diffusion ◽  
The Family ◽  
Bond Network ◽  
Dielectric And Optical Properties ◽  
Bond Rearrangement ◽  
Crystal Bulk

To reveal the structural conditionality for anomalies in physical properties, including dielectric and optical properties, diffraction studies of K9H7(SO4)8·H2O crystals were performed using synchrotron radiation in the temperature range 293–450 K and determined at 405 K, taking H atoms into account. The results indicate that the occurrence of high conductivity in K9H7(SO4)8·H2O crystals with a temperature increase is associated with the outward diffusion of water molecules, hydrogen-bond network rearrangement and the formation of channels for the possible motion of K+ions. A rearranged system of hydrogen bonds consists of permanent bonds and partly of dynamically disordered bonds. Hydrogen-bond rearrangement and the hindered back diffusion of water to the crystal bulk stabilize the high-temperature crystal structure right down to room temperature.

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