Raman and infrared spectroscopic study of the vivianite-group phosphates vivianite, baricite and bobierrite

2002 ◽  
Vol 66 (6) ◽  
pp. 1063-1073 ◽  
Author(s):  
R. L. Frost ◽  
W. Martens ◽  
P. A. Williams ◽  
J. T. Kloprogge
Keyword(s):  
Molecular Structure ◽  
Hydrogen Bonding ◽  
Water Molecules ◽  
Infrared Spectroscopic Study ◽  
Tetrahedral Symmetry ◽  
Phosphate Anions ◽  
Stretching Vibrations ◽  
Bending Modes ◽  
Ir Bands ◽  
Hydrogen Bonded

Abstract The molecular structure of the three vivianite-structure, compositionally related phosphate minerals vivianite, baricite and bobierrite of formula M32+(PO4)2.8H2O where M is Fe or Mg, has been assessed using a combination of Raman and infrared (IR) spectroscopy. The Raman spectra of the hydroxyl-stretching region are complex with overlapping broad bands. Hydroxyl stretching vibrations are identified at 3460, 3281, 3104 and 3012 cm−1 for vivianite. The high wavenumber band is attributed to the presence of FeOH groups. This complexity is reflected in the water HOH-bending modes where a strong IR band centred around 1660 cm−1 is found. Such a band reflects the strong hydrogen bonding of the water molecules to the phosphate anions in adjacent layers. Spectra show three distinct OH-bending bands fromstrongly hydrogen-bonded, weakly hydrogen bonded water and non-hydrogen bonded water. The Raman phosphate PO-stretching region shows strong similarity between the three minerals. In the IR spectra, complexity exists with multiple antisymmetric stretching vibrations observed, due to the reduced tetrahedral symmetry. This loss of degeneracy is also reflected in the bending modes. Strong IR bands around 800 cm−1 are attributed to water librational modes. The spectra of the three minerals display similarities due to their compositions and crystal structures, but sufficient subtle differences exist for the spectra to be useful in distinguishing the species.

scholarly journals Synthesis and crystal structure of a 6-chloronicotinate salt of a one-dimensional cationic nickel(II) coordination polymer with 4,4′-bipyridine

2020 ◽  
Vol 76 (5) ◽  
pp. 599-604
Author(s):  
Nives Politeo ◽  
Mateja Pisačić ◽  
Marijana Đaković ◽  
Vesna Sokol ◽  
Boris-Marko Kukovec
Keyword(s):  
Molecular Structure ◽  
Coordination Polymer ◽  
Three Dimensional ◽  
Polymeric Chain ◽  
Water Molecules ◽  
Sulfate Heptahydrate ◽  
Synthesis And Crystal Structure ◽  
One Dimensional ◽  
Polymeric Chains ◽  
Hydrogen Bonded

A 6-chloronicotinate (6-Clnic) salt of a one-dimensional cationic nickel(II) coordination polymer with 4,4′-bipyridine (4,4′-bpy), namely, catena-poly[[[tetraaquanickel(II)]-μ-4,4′-bipyridine-κ2 N:N′] bis(6-chloronicotinate) tetrahydrate], {[Ni(C10H8N2)(H2O)4](C6H3ClNO2)2·4H2O} n or {[Ni(4,4′-bpy)(H2O)4](6-Clnic)2·4H2O} n , (1), was prepared by the reaction of nickel(II) sulfate heptahydrate, 6-chloronicotinic acid and 4,4′-bipyridine in a mixture of water and ethanol. The molecular structure of 1 comprises a one-dimensional polymeric {[Ni(4,4′-bpy)(H2O)4]2+} n cation, two 6-chloronicotinate anions and four water molecules of crystallization per repeating polymeric unit. The nickel(II) ion in the polymeric cation is octahedrally coordinated by four water molecule O atoms and by two 4,4′-bipyridine N atoms in the trans position. The 4,4′-bipyridine ligands act as bridges and, thus, connect the symmetry-related nickel(II) ions into an infinite one-dimensional polymeric chain extending along the b-axis direction. In the extended structure of 1, the polymeric chains of {[Ni(4,4′-bpy)(H2O)4]2+} n , the 6-chloronicotinate anions and the water molecules of crystallization are assembled into an infinite three-dimensional hydrogen-bonded network via strong O—H...O and O—H...N hydrogen bonds, leading to the formation of the representative hydrogen-bonded ring motifs: tetrameric R 2 4(8) and R 4 4(10) loops, a dimeric R 2 2(8) loop and a pentameric R 4 5(16) loop.

scholarly journals Synthesis, Structural Characterization and Ligand-Enhanced Photo-Induced Color-Changing Behavior of Two Hydrogen-Bonded Ho(III)-Squarate Supramolecular Compounds

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1369 ◽  
Author(s):  
Wang ◽  
Ke ◽  
Feng ◽  
Ho ◽  
Chang ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Uv Light ◽  
Squaric Acid ◽  
Water Molecules ◽  
Light Illumination ◽  
Supramolecular Architecture ◽  
Bridging Ligands ◽  
Coordination Modes ◽  
Oxygen Atoms ◽  
Hydrogen Bonded

Two coordination polymers (CPs) with chemical formulas, [Ho2(C4O4)2(C2O4)(H2O)8]·4H2O (1) and [Ho(C4O4)1.5(H2O)3] (2), (C4O42− = dianion of squaric acid, C2O42− = oxalate), have been synthesized and their structures were determined by single-crystal X-ray diffractometer (XRD). In compound 1, the coordination environment of Ho(III) ion is eight-coordinate bonded to eight oxygen atoms from two squarate, one oxalate ligands and four water molecules. The squarates and oxalates both act as bridging ligands with 1,2-bis-monodentate and bis-chelating coordination modes, respectively, connecting the Ho(III) ions to form a one-dimensional (1D) ladder-like framework. Adjacent ladders are interlinked via O–HO hydrogen bonding interaction to form a hydrogen-bonded two-dimensional (2D) layered framework and then arranged orderly in an AAA manner to construct its three-dimensional (3D) supramolecular architecture. In compound 2, the coordination geometry of Ho(III) is square-antiprismatic eight coordinate bonded to eight oxygen atoms from five squarate ligands and three water molecules. The squarates act as bridging ligands with two coordination modes, 1,2,3-trismonodentate and 1,2-bis-monodentate, connecting the Ho(III) ions to form a 2D bi-layered framework. Adjacent 2D frameworks are then parallel stacked in an AAA manner to construct its 3D supramolecular architecture. Hydrogen bonding interactions between the squarate ligands and coordinated water molecules in 1 and 2 both play important roles on the construction of their 3D supramolecular assembly. Compounds 1 and 2 both show remarkable ligand-enhanced photo-induced color-changing behavior, with their pink crystals immediately turning to yellow crystals under UV light illumination.

Vibrational study and spectra-structure correlations in magnesium disaccharinate heptahydrate, Mg(sac)2⋅7H2O

2008 ◽  
Vol 27 (1) ◽  
pp. 1
Author(s):  
Gligor Jovanovski ◽  
Petre Makreski ◽  
Bojan Šoptrajanov
Keyword(s):  
Experimental Data ◽  
Raman Spectrum ◽  
The Other ◽  
Water Molecules ◽  
Carbonyl Groups ◽  
Structural Units ◽  
Vibrational Study ◽  
Structure Correlations ◽  
Stretching Vibrations ◽  
Ir Bands

Infrared and Raman vibrational spectra of magnesium disaccharinate heptahydrate, Mg(sac)2⋅7H2O, in the 4000–380 cm–1 region (for infrared) and 4000–100 cm–1 region (for Raman) were studied. The assignment of the spectra was based on the experimental data for the previously studied metal saccharinates as well as the literature data for the ab initio calculations on the free deprotonated saccharinato species. Special attention was paid to the analysis of the H2O, CO and SO2 stretching modes. The spectral picture in the regions of the water, carbonyl and sulfonyl stretches is correlated with the number of the crystallographically determined non-equivalent H2O, CO and SO2 structural units. It was found that the presence of seven crystallographically different water molecules in the structure (fourteen different Ow⋅⋅⋅O and Ow⋅⋅⋅N distances) is not reflected in the appearance of the expected fourteen IR bands in the region of the OD stretching vibrations of the isotopically isolated HDO molecules. This must be due to the existence in the structure of several Ow⋅⋅⋅O or Ow⋅⋅⋅N hydrogen bonds with very similar strengths causing an overlap of the corresponding bands in the spectrum. Despite the presence of two carbonyl groups with practically identical C–O distances [124.2(3) and 124.0(3) pm], two clearly separated bands are registered in the carbonyl stretching region of the IR (1660 and 1627 cm–1) and Raman spectrum (1648 and 1620 cm–1). On the other hand, although two nonequivalent SO2 groups are present in the structure of Mg(sac)2⋅7H2O, only one pair of bands due to SO2 stretchings [νas(SO2 and νs(SO2) modes] is registered in the IR spectrum.

More examples of the 15-crown-5...H2O—M—OH2...15-crown-5 motif, M = Al3+, Cr3+ and Pd2+

2010 ◽  
Vol 66 (2) ◽  
pp. 213-221 ◽  
Author(s):  
Maxime A. Siegler ◽  
Jacob H. Prewitt ◽  
Steven P. Kelley ◽  
Sean Parkin ◽  
John P. Selegue ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Water Molecule ◽  
Lattice Water Molecule ◽  
Literature Survey ◽  
The Other ◽  
Water Molecules ◽  
Lattice Water ◽  
Hydrogen Bonding Pattern ◽  
Hydrogen Bonded

Five structures of co-crystals grown from aqueous solutions equimolar in 15-crown-5 (or 15C5) and [M(H2O)6](NO3) n , M = Al3+, Cr3+ and Pd2+, are reported. The hydrogen-bonding patterns in all are similar: metal complexes including the fragment trans-H2O—M—OH2 alternate with 15C5 molecules, to which they are hydrogen bonded, to form stacks. A literature survey shows that this hydrogen-bonding pattern is very common. In each of the two polymorphs of the compound [Al(H2O)6](NO3)3·15C5·4H2O there are two independent cations; one forms hydrogen bonds directly to the 15C5 molecules adjacent in the stack, while the other cation is hydrogen-bonded to two water molecules that act as spacers in the stack. These stacks are then crosslinked by hydrogen bonds formed by the three nitrate counterions and the three lattice water molecules. The hydrogen-bonded stacks in [Cr(H2O)5(NO3)](NO3)2·1.5(15C5)·H2O are discrete rather than infinite; each unit contains two Cr3+ complex cations and three 15C5 molecules. These units are again crosslinked by the uncoordinated nitrate ions and a lattice water molecule. In [Pd(H2O)2(NO3)2]·15C5 the infinite stacks are electrically neutral and are not crosslinked. In [Pd(H2O)2(NO3)2]·2(15C5)·2H2O·2HNO3 a discrete, uncharged unit containing one Pd complex and two 15C5 molecules is `capped off' at either end by a lattice water molecule and an included nitric acid molecule. In all five structures the infinite stacks or discrete units form an array that is at least approximately hexagonal.

Channel- and layer-type anionic host structures in inclusion compounds of urea, tetraalkylammonium terephthalate/trimesate and water

2000 ◽  
Vol 56 (1) ◽  
pp. 142-154 ◽  
Author(s):  
Feng Xue ◽  
Thomas C. W. Mak
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Three Dimensional ◽  
Directed Assembly ◽  
Water Molecules ◽  
Triclinic Space Group ◽  
Dimensional Network ◽  
Graph Set ◽  
Host Lattices ◽  
Hydrogen Bonded

New crystalline adducts of tetraalkylammonium terephthalate/trimesate with urea and water molecules result from hydrogen-bond directed assembly of complementary acceptors and donors, and the anionic host lattices are described using the graph-set notation to identify distinct hydrogen-bonding motifs and patterns. Tetra-n-butylammonium terephthalate–urea–water (1/6/2), C46H104N14O12 (1), triclinic, space group P1¯, a = 8.390 (2), b = 9.894 (2), c = 18.908 (3) Å, α = 105.06 (2), β = 94.91 (1), γ = 93.82 (2)°, Z = 1, is composed of hydrogen-bonded terephthalate–urea layers, which are intersected by urea layers to generate a three-dimensional network containing large channels for accommodation of the cations. Tetraethylammonium terephthalate–urea–water (1/1/5), C25H58N4O10 (2), triclinic, P1¯, a = 9.432 (1), b = 12.601 (1), c = 14.804 (1) Å, α = 79.98 (1), β = 79.20 (1), γ = 84.18 (1)°, Z = 2, has cations sandwiched between hydrogen-bonded anionic layers. Tetraethylammonium trimesate–urea–water (1/2/7.5), C35H86N7O15.5 (3), triclinic, P1¯, a = 13.250 (1), b = 14.034 (1), c = 15.260 (1) Å, α = 72.46 (1), β = 78.32 (1), γ = 66.95 (1)°, Z = 2, manifests a layer-type structure analogous to that of (2). Tetra-n-propylammonium hydrogen trimesate–urea–water (1/2/5), C35H78N6O13 (4), orthorhombic, Pna21, a = 16.467 (3), b = 33.109 (6), c = 8.344 (1) Å, Z = 4, features hydrogen trimesate helices in a three-dimensional host architecture containing nanoscale channels each filled by a double column of cations.

Structure–activity studies of β-carbolines. 1. Molecular structure and conformation of cis-3-carboxylic acid-1,2,3,4-tetrahydroharmane dihydrate

1983 ◽  
Vol 61 (3) ◽  
pp. 529-532 ◽  
Author(s):  
Penelope W. Codding
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Carboxylic Acid ◽  
Benzodiazepine Receptor ◽  
Chair Conformation ◽  
Water Molecules ◽  
Space Group ◽  
Structure Activity ◽  
Packing Arrangement

The crystal structure of cis-3-carboxylic acid-1,2,3,4-tetrahydroharmane dihydrate, C13H13N2O2•2H2O, a putative ligand of the benzodiazepine receptor is reported. The space group is P21/c with a = 14.850(4), b = 6.560(3), c = 14.746(4) Å and β = 117.411(8)°, Z = 4. The molecule crystallizes as a zwitterion with the unsaturated ring in a half-chair conformation. Hydrogen bonding to the water molecules included in the lattice determines the molecular packing arrangement.

RAMAN AND FTIR SPECTRA OF RE(BrO3)3·9H2O(RE = Eu, Tb) AND ELECTRONIC TRANSITIONS IN Eu(BrO3)3·9H2O

2001 ◽  
Vol 15 (18) ◽  
pp. 2499-2507 ◽  
Author(s):  
M. J. BUSHIRI ◽  
V. U. NAYAR
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Raman Spectra ◽  
Structural Data ◽  
Ftir Spectra ◽  
Free State ◽  
Electronic Transitions ◽  
Water Molecules ◽  
Spectral Pattern ◽  
Bending Modes

Raman, FTIR spectra of Eu ( BrO 3)3·9 H 2 O and Tb ( BrO 3)3·9 H 2 O are recorded and analyzed. The observed bands are assigned on the basis of [Formula: see text] and H 2 O vibrations. Electronic transitions observed in the Raman spectra of Eu ( BrO 3)3· 9 H 2 O are also investigated. In Tb ( BrO 3)3·9 H 2 O the symmetry of [Formula: see text] anion is lowered from C 3 v to C s due to distortion. The wavenumber value of the ν1 mode of [Formula: see text] anion is found to be decreased from that of free state and is due to hydrogen bonding in the crystal. The decrease in wavenumber values of stretching modes and the increase in wavenumber values of the bending modes of water molecules from free state values confirm that they form hydrogen bonds with oxygen atoms are bromate ions in agreement with the structural data. Further the spectral pattern of water molecules indicates the presence of hydrogen bonds of varying strengths. The electronic transitions observed in Eu ( BrO 3)3·9 H 2 O suggest that Eu 3+ ions are situated in the crystal at sites having symmetry higher than C 2 or C 1.

Hydrogen bonding and vapor pressure isotope effect of ethanethiol

1979 ◽  
Vol 57 (11) ◽  
pp. 1350-1353 ◽  
Author(s):  
Jerzy Szydlowski ◽  
Hans Wolff
Keyword(s):  
Hydrogen Bonding ◽  
Vapor Pressure ◽  
Isotope Effect ◽  
Inverse Effect ◽  
Apparent Decrease ◽  
Stretching Vibrations ◽  
Intermolecular Vibrations ◽  
Hydrogen Bonded

The vapor pressure ratios of ethanethiol and ethanethiol-d1 between 223 and 323 K can be represented by the relation[Formula: see text]The PD/PH vs. T curve increases initially and reaches a flat maximum at 293 K; at higher temperatures there is an apparent decrease. This behavior can be explained by the superposition of predominantly the normal effect of the intermolecular vibrations and the SH and SD torsion vibrations, and the inverse effect of the SH and SD stretching vibrations. Contrary to the value of 0.91 reported previously, PD/PH values of 1.002 to 1.008 confirm that for weakly hydrogen-bonded substances and their deuterium-bonded analogues a negligibly normal or a slightly inverse vapor pressure isotope effect should be observed.

The Hydrate of Hexafluorophosphoric Acid

1972 ◽  
Vol 50 (21) ◽  
pp. 3515-3520 ◽  
Author(s):  
D. W. Davidson ◽  
S. K. Garg
Keyword(s):  
Hydrogen Bonding ◽  
Chemical Analysis ◽  
Resonance Line ◽  
Water Molecules ◽  
Rigid Lattice ◽  
Proton Diffusion ◽  
Rapid Proton ◽  
Hydrogen Bonded

HPF6 is said to form a hexahydrate of a unique clathrate structure in which [Formula: see text] ions occupy truncated-octahedral cages in a framework of hydrogen-bonded water molecules. N.m.r. studies show, however, that appreciable quantities of HF are incorporated in the lattice and that the composition is more properly [Formula: see text], a result supported by chemical analysis. H3O+ and HF appear to be distributed over the lattice sites previously assigned to water molecules so as to involve all H atoms in the hydrogen bonding. The 1H resonance line is narrowed by rapid proton diffusion down to 150 °K. The 19F line of encaged [Formula: see text] is narrowed by rotation above 75 °K and reaches the rigid-lattice shape only below 25 °K.

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