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.

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.

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.

Infrared Studies of Water in Crystalline Hydrates: K2CuCl4•2H2O

1974 ◽  
Vol 52 (7) ◽  
pp. 1029-1041 ◽  
Author(s):  
Gwen H. Thomas ◽  
Michael Falk ◽  
Osvald Knop
Keyword(s):  
Crystal Structure ◽  
Water Molecule ◽  
Infrared Spectra ◽  
Vibrational Spectra ◽  
Distinct Type ◽  
Vibrational Coupling ◽  
Infrared Studies ◽  
Crystalline Hydrates

Infrared spectra of polycrystalline K2CuCl4•2H2O at different degrees of deuteration were recorded, between 4000 and 300 cm−1, at temperatures from −160 to 90 °C. The spectra confirm the existence of only one crystallographically distinct type of water molecule in the structure, on sites of symmetry C2r. Vibrational coupling of the bending fundamentals of the water molecule has been analyzed in detail. It is shown that the existence and magnitude of such coupling may be used to predict, from the spectrum of a hydrate, the manner in which a water molecule participates in the crystal structure. The structure and the vibrational spectra of K2CuCl4•2H2O are compared with those of the closely related CuCl2•2H2O.

Crystal Structure of Calcium Picrate Pentahydrate: A New Eight-Coordinate Stereochemistry for [M(bidentate)2(unidentate)4]

1979 ◽  
Vol 32 (2) ◽  
pp. 301 ◽  
Author(s):  
V Diakiw ◽  
TW Hambley ◽  
DL Kepert ◽  
CL Raston ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Water Molecule ◽  
Single Crystal ◽  
Title Compound ◽  
Lattice Site ◽  
The Other ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Triangular Face ◽  
X Ray

The crystal structure of the title compound, Ca(C6H2N307)2,5H2O, has been determined by single-crystal X-ray diffraction at 295(1) K and refined by least squares to a residual of 0.049 for 1513 'observed' reflections. Crystals are orthorhombic, Pmab, a 24.169(6), b l0.292(7), c 8.554(2) �, Z 4. The stereochemistry about the calcium has not been observed previously for the system [M(bidentate)2- (unidentate)4]; in the present structure, the calcium is coordinated by a pair of bidentate picrate ligands and the four water molecules in an array in which three of the water molecules occupy a triangular face of a square antiprism, the overall array having m symmetry. The remaining water molecule occupies a lattice site with no close interaction with the other species.

Ligand Hyperfine Interaction in the Complex [Mn(H2O)6] ++ in La2(Mg,Mn)3(NO3)12·24H2O

1969 ◽  
Vol 24 (11) ◽  
pp. 1746-1751 ◽  
Author(s):  
D. van Ormondt ◽  
R. de Beer ◽  
M. Brouha ◽  
F. de Groot
Keyword(s):  
Simple Model ◽  
Water Molecule ◽  
Hyperfine Interaction ◽  
Principal Direction ◽  
The Other ◽  
Water Molecules ◽  
Manganese Ion ◽  
Interaction Tensor ◽  
Principal Directions

Abstract The elements of the hyperfine interaction (h.f.i.) between the manganese ion and the protons in the complex [Mn(H2O)6]++ in one of the two possible sites in La2(Mg, Mn)3(NO3)12 · 24 H2O have been measured with ENDOR at 15 to 20 K. The six water molecules in the complex at the chosen site are equivalent for reasons of symmetry.One principal direction of the h.f.i. tensor of each proton is found to be perpendicular to the Mn, O line. With the assumption that each proton is located in the plane of the other two principal directions of its interaction tensor the positions of the protons are evaluated from the anisotropic parts of the h.f.i. tensors. In this calculation the effect of covalency on the anisotropic h.f.i. is ac-counted for with the aid of a simple model.The isotropic h.f.i.'s with the two protons of a water molecule appear to be very nearly equal (+ 0.890 MHz for both). This latter result is remarkable in view of the fact that one proton is distinctly nearer to the manganese ion than the other.

scholarly journals Poly[[tetra-μ-cyanido-κ8C:N-dodeca-cyanido-κ12C-tris(N,N-dimethylformamide-κO)tris(methanol-κO)tris(3,4,7,8-tetramethyl-1,10-phenanthroline-κ2N,N′)trimanganese(II)ditungstate(V)] dihydrate]

2014 ◽  
Vol 70 (5) ◽  
pp. m170-m171
Author(s):  
Fei-Lin Yang ◽  
Dan Yang
Keyword(s):  
Water Molecule ◽  
Title Compound ◽  
Chain Structure ◽  
Octahedral Geometry ◽  
The Other ◽  
Distorted Octahedral Geometry ◽  
Water Molecules ◽  
Asymmetric Unit ◽  
Π Interactions ◽  
Distorted Octahedral

The asymmetric unit of the title compound, {[Mn3{W(CN)8}2(C16H16N2)3(C3H7NO)3(CH3OH)3]·2H2O}n, consists of three [Mn(N,N-dimethylformamide)(methanol)(3,4,7,8-tetramethyl-1,10-phenanthroline)]2+cations, two [W(CN)8]3−anions and two water molecules. Each water molecule is disordered over three sets of sites, with a refined occupancy ratio of 0.310 (9):0.275 (9):0.415 (9) for one molecule and 0.335 (9):0.288 (9):0.377 (9) for the other molecule. The MnIIatoms exhibit a distorted octahedral geometry, while the WVatoms adopt a distorted square-antiprismatic geometry. The MnIIand WVatoms are linked alternatively through cyanide groups, forming a tetranuclear 12-atom rhombic metallacycle. Adjacent metallacycles are further connected by μ2-bridging cyanide anions, generating a 3,2-chain structure running parallel to [101]. Interchain π–π interactions are observed [centroid–centroid distances = 3.763 (3) and 3.620 (2) Å].

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.

scholarly journals Properties of cupric ions in benzylamine oxidase from pig plasma as studied by magnetic-resonance and kinetic methods

1979 ◽  
Vol 177 (1) ◽  
pp. 289-302 ◽  
Author(s):  
R Barker ◽  
N Boden ◽  
G Cayley ◽  
S C Charlton ◽  
R Henson ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Water Molecule ◽  
Isoelectric Focusing ◽  
Gel Electrophoresis ◽  
Analytical Ultracentrifugation ◽  
The Other ◽  
Water Molecules ◽  
Fast Exchange ◽  
Benzylamine Oxidase ◽  
O2 Binding

Benzylamine oxidase from pig plasma has been studied by a variety of chemical and physical techniques. 1. Analytical ultracentrifugation, gel electrophoresis and isoelectric-focusing studies suggest that the enzyme is composed of two subunits with closely similar primary structures. 2. E.s.r. and n.m.r. measurements show that the enzyme contains two well-separated (greater than 0.6 nm) Cu2+ ions at chemically distinct sites. Each Cu2+ ion is coordinated by two water molecules, one ‘axial’ and the other ‘equatorial’. Both water molecules undergo fast exchange (10(5)–10(8) s-1) with solvent and are deprotonated in the pH r!ange 8–9, but only the equatorial water molecule is displaced by the inhibitors N3- and CN-. 3. Kinetic and e.s.r. measurements show that azide and cyanide compete against O2 binding and also make the two Cu2+ sites identical. It is concluded that Cu2+ must participate in the re-oxidation of reduced enzyme by molecular O2.

Infrared studies of DNA, water, and inositol associations

1968 ◽  
Vol 46 (7) ◽  
pp. 691-695 ◽  
Author(s):  
S. J. Webb ◽  
J. S. Bhorjee
Keyword(s):  
Infrared Spectra ◽  
Water Molecules ◽  
Large Decrease ◽  
Bacterial Dna ◽  
Dichroic Ratio ◽  
Biological Phenomena ◽  
Oriented Films ◽  
Infrared Studies

Ultraviolet and polarized infrared spectra of oriented films of bacterial DNA have been recorded over a range of relative humidities (R.H.) between 10 and 84%. The films were made from a DNA gel in H2O or D2O with and without 5% (w/v) myo-inositol. In the absence of inositol a large decrease in the dichroic ratio at 1670 cm−1 occurred as the R.H. was lowered between 70 and 30%, indicating the occurrence of considerable disorganization. This was not observed when the DNA was dehydrated in the presence of myo-inositol. A marked increase in absorbance at 2600 Å which occurred on lowering the R.H. from 70 to 50% was prevented also by inositol.These results indicate that myo-inositol can replace water molecules and maintain the DNA in the B configuration during dehydration. The possible significance of these observations in the explanation of certain biological phenomena is discussed.

Diaquatetrakis(1,3-di-4-pyridylpropane-κN)manganese(II) bis(hexafluoridophosphate) monohydrate

2007 ◽  
Vol 63 (11) ◽  
pp. m2682-m2683 ◽  
Author(s):  
Xianfu Zheng ◽  
Caoyuan Niu ◽  
Xinsheng Wan ◽  
Chunhong Kou
Keyword(s):  
Hydrogen Bonds ◽  
Water Molecule ◽  
Metal Center ◽  
The Other ◽  
Water Molecules ◽  
Asymmetric Unit ◽  
Solvent Water Molecule ◽  
Solvent Water

The title mononuclear MnII complex, [Mn(C13H14N2)4(H2O)2](PF6)2·H2O, is isostructural with the previously reported ZnII complex. The metal center is coordinated by four monodentate 1,3-di-4-pyridylpropane (L1) ligands and two water molecules. One L1 ligand is affected by disorder of two propane C atoms, which are distributed over two positions, with occupancies 0.771 (8)/0.229 (8). The asymmetric unit is completed by one solvent water molecule and two PF6 − anions, both disordered over two positions, with occupancies for F atoms of 0.621 (10)/0.379 (10) for one anion and 0.69 (2)/0.31 (2) for the other. Uncoordinated N atoms of pyridyl groups belonging to L1 and water molecules are involved in hydrogen bonds, with D...A separations ranging from 1.85 (4) to 2.07 (4) Å and D—H...A angles from 169 (3) to 174 (4)°.

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