Infrared Studies of Water in Crystalline Hydrates: Location of Hydrogen Atoms and Evidence for a Bifurcated Hydrogen Bond in K2SnCl4•H2O

1974 ◽  
Vol 52 (13) ◽  
pp. 2380-2388 ◽  
Author(s):  
Michael Falk ◽  
Chung-Hsi Huang ◽  
Osvald Knop
Keyword(s):  
Hydrogen Bonding ◽  
Spectral Characteristics ◽  
Supplementary Information ◽  
Water Molecules ◽  
Dynamic Coupling ◽  
Hydrogen Atoms ◽  
Infrared Studies ◽  
Infrared Spectral ◽  
Bifurcated Hydrogen Bond ◽  
Crystalline Hydrates

Infrared spectra of polycrystalline K2SnCl4•H2O at different degrees of deuteration were recorded between 4000 and 300 cm−1 at temperatures between 30 and −160 °C. The spectra are consistent with the crystal structure proposed by Kamenar and Grdenić. The water molecules are all equivalent and asymmetric. They are sufficiently well separated from one another for the dynamic coupling of vibrations to be negligible. Both hydrogens of the water molecule participate in hydrogen bonding; one of the hydrogen bonds is weak and bifurcated. Positional parameters of the hydrogen atoms have been calculated using supplementary information from available n.m.r. studies. Infrared spectral characteristics of water molecules engaged in bifurcated hydrogen bonding are discussed.

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: 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.

scholarly journals Notizen: Hydrogen Bonding in MoO2Cl2 · H2O Determined by Electrostatic Energy Calculations

1977 ◽  
Vol 32 (11) ◽  
pp. 1358-1359 ◽  
Author(s):  
Werner H. Baur
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Systematic Variation ◽  
Electrostatic Energy ◽  
Water Molecules ◽  
Hydrogen Atoms ◽  
Energy Calculations ◽  
Internal Geometry

The configuration of least electrostatic energy for the hydrogen atoms in both polytypes of MoO2Cl2 · H2O was obtained by systematic variation of the orientations of the water molecules. The internal geometry of the H2O group was kept constant throughout the variation. The hydrogen bonds are of the bifurcated type: [xxx]

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.

Conformation of the esters of steroid hydroxyl groups by infrared spectroscopy

1969 ◽  
Vol 47 (9) ◽  
pp. 1601-1603 ◽  
Author(s):  
C. R. Narayanan ◽  
M. R. Sarma ◽  
T. K. K. Srinivasan ◽  
M. S. Wadia
Keyword(s):  
Hydrogen Bonding ◽  
Infrared Spectroscopy ◽  
Carbonyl Group ◽  
Hydroxyl Group ◽  
Spectral Studies ◽  
Hydroxyl Groups ◽  
Hydrogen Atoms ◽  
Infrared Spectral

Infrared spectral studies show that the carbonyl group of the esters of steroid hydroxyl groups are stabilized near the adjacent alkyl hydrogen atoms; this energy of stabilization appears to be more than that of hydrogen bonding between the carbonyl and a nearby hydroxyl group.

scholarly journals The Crystal Structures of Two Hydro-closo-Borates with Divalent Tin in Comparison: Sn(H2O)3[B10H10] · 3 H2O and Sn(H2O)3[B12H12] · 4 H2O

2021 ◽  
Author(s):  
Fabian M. Kleeberg ◽  
Lucas W. Zimmermann ◽  
Thomas Schleid
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Single Crystals ◽  
Water Molecules ◽  
Hydrogen Atoms ◽  
Crystal Water ◽  
Boron Clusters ◽  
Triclinic System ◽  
Isothermal Evaporation ◽  
Tin Metal

AbstractSingle crystals of Sn(H2O)3[B10H10] · 3 H2O and Sn(H2O)3[B12H12] · 4 H2O are easily accessible by reactions of aqueous solutions of the acids (H3O)2[B10H10] and (H3O)2[B12H12] with an excess of tin metal powder after isothermal evaporation of the clear brines. Both compounds crystallize with similar structures in the triclinic system with space group P$$\bar{1 }$$ 1 ¯ and Z = 2. The crystallographic main features are electroneutral $${}_{\infty }^{1} \{$$ ∞ 1 { Sn(H2O)3/1[B10H10]3/3} and $${}_{\infty }^{1} \{$$ ∞ 1 { Sn(H2O)3/1[B12H12]3/3} double chains running along the a-axes. Each Sn2+ cation is coordinated by three water molecules of hydration (d(Sn–O) = 221–225 pm for the B10 and d(Sn–O) = 222–227 pm for the B12 compound) and additionally by hydridic hydrogen atoms of the three nearest boron clusters (d(Sn–H) = 281–322 pm for the B10 and d(Sn–H) = 278–291 pm for the B12 compound), which complete the coordination sphere. Between these tin(II)-bonded water and the three or four interstitial crystal water molecules, classical bridging hydrogen bonds are found, connecting the double chains to each other. Furthermore, there is also non-classical hydrogen bonding between the anionic [BnHn]2− (n = 10 and 12) clusters and the crystal water molecules pursuant to B–Hδ−$$\cdots$$ ⋯ δ+H–O interactions often called dihydrogen bonds.

2. The water molecule and its interactions

2015 ◽  
pp. 14-23
Author(s):  
John Finney
Keyword(s):  
Hydrogen Bonding ◽  
Electrical Properties ◽  
Oxygen Atom ◽  
Water Molecule ◽  
Water Molecules ◽  
Hydrogen Atoms ◽  
Covalent Bonds ◽  
Structure Of Water ◽  
Wide Range ◽  
Structural And Electrical Properties

‘The water molecule and its interactions’ discusses the structural and electrical properties of the water molecule. A water molecule is made up of two hydrogen atoms connected by covalent bonds to one oxygen atom. Water molecules interact with each other through a type of interaction called hydrogen bonding. A tetrahedral arrangement of four water molecules around a central one is the key to understanding water. It helps to explain the structure of water in its various states, its properties, and how it interacts with other kinds of molecules, allowing exploration of the properties and behaviour of the wide range of chemical, physical, and biological systems in which water is involved.

scholarly journals A Theoretical and Experimental Study on Hydrogen-bonding Interactions between 4H-1,2,4-triazole-3,5-diamine and DMSO/water

2020 ◽  
Vol 39 (1) ◽  
pp. 65
Author(s):  
Mustafa Tuğfan Bilkan
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Density Functional ◽  
Energy Difference ◽  
Water Molecules ◽  
Hydrogen Atoms ◽  
Hydrogen Bond Acceptor ◽  
Functional Theory ◽  
Hydrogen Bonding Interactions ◽  
Aqueous Complexes

In this paper, 4TZDA-DMSO/water complexes formed by hydrogen bonding interactions were investigated by a combined experimental and computational approach. Two conformations of 4TZDA molecule were considered. Seven hydrogen-bonded 4TZDA-DMSO/H2O complexes were characterized in terms of geometries, energies and vibrational frequencies. The optimizations and calculations were performed for the complexes by Density Functional Theory. In the experimental part, the DMSO/H2O solutions of 4TZDA were prepared and infrared spectra of the solutions were recorded. After the solvation process, significant shifts in the existing bands and new band rising were observed in the experimental spectra of 4TZDA. Following results are found from this study: 1) 4TZDA (I) is more stable than 4TZDA (II). 2) Seven 4TZDA-DMSO and 4TZDA-H2O complexes are investigated and it is seen that all nitrogen atoms of 4TZDA are hydrogen bond acceptor and all hydrogen atoms are hydrogen bond donors. 3) Aqueous complexes of 4TZDA are found to form stronger hydrogen bonds compared to DMSO complexes. 4) It is determined that the most stable structures are intermolecular interactions of lpO⋯H-N and lpN⋯H-O type for the complexes. For these interactions, h-bond lengths are calculated as 1.78 and 1.90 Å and interaction energies are -7.10 kJ/mol for 4TZDA-DMSO and -50.5 kJ/mol for 4TZDA-H2O. Because of this energy difference in the complexes, it can be said 4TZDA forms more stable complexes with water molecules compared to DMSO molecules and with this property, it is an ideal molecule for pharmacological purposes.

Infrared Studies of the Dynamic Aspects of Hydrogen-Bonding in Hydroxylated Metabolites of 2,5,2′,5′,-Tetrachlorobiphenyl

1976 ◽  
Vol 59 (5) ◽  
pp. 993-1002
Author(s):  
Jo-Yun T Chen
Keyword(s):  
Hydrogen Bonding ◽  
Dynamic Equilibrium ◽  
Spectral Studies ◽  
Ortho Position ◽  
Oh Groups ◽  
Rotational Isomers ◽  
Hydroxylated Metabolites ◽  
Infrared Studies ◽  
Infrared Spectral ◽  
Cis And Trans

Abstract Infrared spectral studies indicate that the hydroxylated 2,5,2′,5′-tetrachlorobiphenyls (TCBs) exist in a dynamic equilibrium of free, intramolecular, and intermolecular hydrogen-bonded forms. The relative abundances of the various species depend upon the polarity of the solvents as well as the physical state of the compound resulting from different configurations, i.e., the monohydroxylated 2,5,2′,5′-TCBs exist as cis and trans rotational isomers of OH with respect to the chlorine atom in the ortho position, and 3,4-dihydro-3,4-dihydroxy-2,5,2′,5′-TCB exists as 2 trans conformers with the OH groups either axial-axial or equatorial-equatorial with respect to the plane of the attached ring. In the solid state, the dimer or polymer is preferred with intermolecular hydrogen-bonding occurring between OH groups.

Infrared Studies of Water in Crystalline Hydrates: K2FeCl5·H2O (Erythrosiderite) and Related Aquopentachloroferrates(III)

1975 ◽  
Vol 53 (1) ◽  
pp. 51-57 ◽  
Author(s):  
Michael Falk ◽  
Chung-Hsi Huang ◽  
Osvald Knop
Keyword(s):  
Water Molecule ◽  
Infrared Spectra ◽  
Water Molecules ◽  
High Charge ◽  
Infrared Studies ◽  
Approximate Location ◽  
Crystalline Hydrates

Infrared spectra of M2[FeCl5(H2O)] (M = K, Rb, NH4) at different degrees of deuteration were recorded, between 4000 and 300 cm−1, at 30 and −160 °C. The spectra of the three compounds were closely similar, as was that of natural K2[FeCl5(H2O)] (erythrosiderite). They indicate the existence of only one type of water molecule in the structure. The water molecules are symmetric, well separated from one another, and engage in O—H … Cl bonds with O … Cl distances of about 3.22 Å, as estimated from the OH and OD stretching frequencies. These conclusions support the structure proposed for K2[FeCl5(H2O)] by Bellanca and lead to approximate location of the H atoms. The observed mixing of the librational and translational modes, which occurs when the frequencies of translational modes are high, may be characteristic of H2O molecules coordinated to cations of high charge.

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