scholarly journals Structure and hydrogen bonding of the hydrated selenite and selenate ions in aqueous solution

2014 ◽  
Vol 43 (17) ◽  
pp. 6315-6321 ◽  
Author(s):  
Lars Eklund ◽  
Ingmar Persson
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Bonding ◽  
Free Electron ◽  
Electron Pair ◽  
Bound Water ◽  
Water Molecules ◽  
Hydration Sphere ◽  
Free Electron Pair

The selenite ion has an asymmetric hydration sphere with loosely electrostatically bound water molecules outside the free electron pair.

Darstellung und Kristallstruktur von K2Sb4S7 · H2O / Preparation and Crystal Structure of K2Sb4S7 · H2O

1979 ◽  
Vol 34 (3) ◽  
pp. 383-385 ◽  
Author(s):  
Brigitte Eisenmann ◽  
Herbert Schäfer
Keyword(s):  
Crystal Structure ◽  
Free Electron ◽  
Electron Pair ◽  
Three Dimensional ◽  
The Other ◽  
Water Molecules ◽  
Triclinic System ◽  
Dimensional Network ◽  
Free Electron Pair

Abstract K2Sb4S7 · H2O crystallizes in the triclinic system with a = 1171.4(5) pm, b = 952.0(5) pm, c = 715.6(5) pm and α = 99.36(5)°, β = 86.80(5)°, γ= 103.48(5)°. One half of the Sb atoms has three sulfur neighbours forming with the free electron pair a ψ-ShS3 tetrahedron, while the other half is coordinated by four S atoms to build a ψ-trigonal SbS4 bipyramid. These polyhedra are connected by common edges and corners to a three-dimensional network with two types of channels, in which either K+ ions only or K+ ions and water molecules are located.

Electronic effects on enol acidity and keto-enol equilibrium constants for ring-substituted 2-tetralones

1999 ◽  
Vol 77 (5-6) ◽  
pp. 634-638 ◽  
Author(s):  
Xudong Yao ◽  
Ralph M Pollack
Keyword(s):  
Aqueous Solution ◽  
Charge Transfer ◽  
Systematic Study ◽  
Free Electron ◽  
Electron Pair ◽  
Equilibrium Constants ◽  
Hydroxyl Group ◽  
Negative Deviation ◽  
Electronic Effects ◽  
Free Electron Pair

Equilibrium constants for the ionization of a variety of phenyl-substituted 2-tetralones (pKaK), for the ionization of their enols (pKaE), and for keto-enol tautomerization (pKE) were determined. Hammett plots of pKaK and pKaE vs. σ- are linear with slopes (-ρ) of -1.66 ± 0.06 and -0.90 ± 0.03, respectively, except for deviations of the points corresponding to 6-nitro-2-tetralone (1b) and its enol. We have previously attributed the negative deviation of 1b from the correlation for the acidities of the ketones obtained with the more limited set of data to the lack of a free electron pair on C-1 of the free tetralone (Nevy et al.). The negative deviation of the point for 1b from the correlation for the acidities of the enols suggests that charge transfer from the hydroxyl group of the enol to the nitro group is less important than it is for phenols. This study represents the first systematic study of electronic effects on equilibria among ketone, enol, and enolate in aqueous solution. Key words: enol, acidity, equilibrium, substituent, conjugation.

Organic Sulfur Mechanisms. 17. A Brief Study of the Photolysis of an Unsaturated Cyclic Sulfone

1975 ◽  
Vol 53 (23) ◽  
pp. 3656-3659 ◽  
Author(s):  
J. F. King ◽  
E. G. Lewars ◽  
D. R. K. Harding ◽  
R. M. Enanoza
Keyword(s):  
Free Electron ◽  
Ring Opening ◽  
Electron Pair ◽  
Heterocyclic Ring ◽  
Organic Sulfur ◽  
Free Electron Pair

Photolysis of 3-phenyl-2H-thiopyran 1,1-dioxide (3) in methanol gives a mixture of 3-phenyl-5-methoxy-5,6-dihydro-2H-thiopyran 1,1-dioxide (4) and methyl 4-phenyl-2,4-pentadiene-1-sulfonate (5). Formation of 5 shows that the photochemical ring opening of cyclohexadienic sulfonyl compounds (1) does not require an atom bearing a free electron pair in the heterocyclic ring, and therefore argues in favor of a mechanism involving cycloreversion to the sulfene (1 → 2).

scholarly journals Crystal structures of four dimeric manganese(II) bromide coordination complexes with various derivatives of pyridine N-oxide

2019 ◽  
Vol 75 (8) ◽  
pp. 1284-1290
Author(s):  
Sheridan Lynch ◽  
Genevieve Lynch ◽  
Will E. Lynch ◽  
Clifford W. Padgett
Keyword(s):  
Hydrogen Bonding ◽  
Solvent Molecule ◽  
Bound Water ◽  
Manganese Atom ◽  
Coordination Complexes ◽  
Water Molecules ◽  
Inversion Center ◽  
Dimeric Complex ◽  
Bromide Ions ◽  
Derivatives Of

Four manganese(II) bromide coordination complexes have been prepared with four pyridine N-oxides, viz. pyridine N-oxide (PNO), 2-methylpyridine N-oxide (2MePNO), 3-methylpyridine N-oxide (3MePNO), and 4-methylpyridine N-oxide (4MePNO). The compounds are bis(μ-pyridine N-oxide)bis[aquadibromido(pyridine N-oxide)manganese(II)], [Mn2Br4(C5H5NO)4(H2O)2] (I), bis(μ-2-methylpyridine N-oxide)bis[diaquadibromidomanganese(II)]–2-methylpyridine N-oxide (1/2), [Mn2Br4(C6H7NO)2(H2O)4]·2C6H7NO (II), bis(μ-3-methylpyridine N-oxide)bis[aquadibromido(3-methylpyridine N-oxide)manganese(II)], [Mn2Br4(C6H7NO)4(H2O)2] (III), and bis(μ-4-methylpyridine N-oxide)bis[dibromidomethanol(4-methylpyridine N-oxide)manganese(II)], [Mn2Br4(C6H7NO)4(CH3OH)2] (IV). All the compounds have one unique MnII atom and form a dimeric complex that contains two MnII atoms related by a crystallographic inversion center. Pseudo-octahedral six-coordinate manganese(II) centers are found in all four compounds. All four compounds form dimers of Mn atoms bridged by the oxygen atom of the PNO ligand. Compounds I, II and III exhibit a bound water of solvation, whereas compound IV contains a bound methanol molecule of solvation. Compounds I, III and IV exhibit the same arrangement of molecules around each manganese atom, ligated by two bromide ions, oxygen atoms of two PNO ligands and one solvent molecule, whereas in compound II each manganese atom is ligated by two bromide ions, one O atom of a PNO ligand and two water molecules with a second PNO molecule interacting with the complex via hydrogen bonding through the bound water molecules. All of the compounds form extended hydrogen-bonding networks, and compounds I, II, and IV exhibit offset π-stacking between PNO ligands of neighboring dimers.

scholarly journals Water Adsorption to Leaves of Tall Cryptomeria japonica Tree Analyzed by Infrared Spectroscopy under Relative Humidity Control

Plants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1107
Author(s):  
Wakana A. Azuma ◽  
Satoru Nakashima ◽  
Eri Yamakita ◽  
Tamihisa Ohta
Keyword(s):  
Hydrogen Bonding ◽  
Relative Humidity ◽  
Cryptomeria Japonica ◽  
Water Adsorption ◽  
Bound Water ◽  
Free Water ◽  
High Water ◽  
Water Molecules ◽  
Cross Sectional ◽  
Tissue Properties

Leaf water storage is a complex interaction between live tissue properties (anatomy and physiology) and physicochemical properties of biomolecules and water. How leaves adsorb water molecules based on interactions between biomolecules and water, including hydrogen bonding, challenges our understanding of hydraulic acclimation in tall trees where leaves are exposed to more water stress. Here, we used infrared (IR) microspectroscopy with changing relative humidity (RH) on leaves of tall Cryptomeria japonica trees. OH band areas correlating with water content were larger for treetop (52 m) than for lower-crown (19 m) leaves, regardless of relative humidity (RH). This high water adsorption in treetop leaves was not explained by polysaccharides such as Ca-bridged pectin, but could be attributed to the greater cross-sectional area of the transfusion tissue. In both treetop and lower-crown leaves, the band areas of long (free water: around 3550 cm−1) and short (bound water: around 3200 cm−1) hydrogen bonding OH components showed similar increases with increasing RH, while the band area of free water was larger at the treetop leaves regardless of RH. Free water molecules with longer H bonds were considered to be adsorbed loosely to hydrophobic CH surfaces of polysaccharides in the leaf-cross sections.

scholarly journals Raman spectroscopic study of the hydration of short-chain poly(oxyethylene)s C 1EnC 1 (n=1−4)

2004 ◽  
Vol 2 (4) ◽  
pp. 617-626 ◽  
Author(s):  
Mircho Georgiev ◽  
Tatiana Popova ◽  
Zhorro Nickolov ◽  
Nikolay Goutev ◽  
Georgi Georgiev ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Bonding ◽  
Raman Band ◽  
Short Chain ◽  
Water Molecules ◽  
Degree Of Hydration ◽  
Raman Spectroscopic ◽  
Raman Spectroscopic Study ◽  
Ether Oxygen ◽  
Oxygen Atoms

AbstractThe hypothesis that the degree of hydration of poly(oxyethylene) (POE) in aqueous solution depends on the mole ratio of water molecules to ether oxygen atoms in the molecule has been verified by studying the isotropic Raman spectra in the O−H stretching region for four short-chain POEs (C 1EnC 1 withn=1−4). Excellent coincidence of the O−H stretching Raman band for all four POEs studied in the range of mole ratio H2O/Oether from 25 to 0.6 was observed, thus confirming the assumption stated above. A conclusion that all ether oxygen atoms in the POE molecule participate in hydrogen bonding with water molecules has been made.

Zum Bindungszustand des fünf- und sechsbindigen Siliciums in kationischen und anionischen o-Arylendioxychelaten / (d ← n) π-Bonding in Anionic and Cationic o-Arylenedioxy Chelates of Hexacoordinate and Pentacoordinate Silicon Studied by Means of ESCA

1974 ◽  
Vol 29 (1-2) ◽  
pp. 72-74 ◽  
Author(s):  
Heinrich Meyer ◽  
Günter Nagorsen
Keyword(s):  
Linear Correlation ◽  
Free Electron ◽  
Linear Relation ◽  
Good Yield ◽  
Electron Pair ◽  
Binding Energies ◽  
Considerable Extent ◽  
Silicon Compounds ◽  
Back Donation ◽  
Free Electron Pair

The “Si-2s- and Si-2p-binding energies” of 5 o-arylenedioxy complexes containing penta- and hexacoordinate silicon have been obtained from their ESCA-spectra. The data have been compared to those of tetracovalent silicon compounds. A linear correlation between calculated Pauling charges and binding energies has been found for compounds where no (d ← n) -interaction should exist. Characteristic deviations from the linear relation were found both in tetravalent silicon compounds containing Si-O-bonds, the (d ← n)π-interaction of which is well established, and in the anionic tris(o-phenylenedioxy) siliconate and in the bis(o-phenylenedioxy) organosiliconates. No deviations were observed in case of the cationic 6-coordinate complexes of silicon with acetylacetone and 2-hydroxypyridine-N-oxide. We conclude that an additional back donation from the free electron pair (dSi ← nOo) only exists to a considerable extent in tetracovalent silicic ester derivatives, in the hexa- and pentacoordinate tris(o-phenylendioxy) siliconate and in the bis(o-phenylenedioxy) organosiliconates. A method is given to obtain crystalline tris(2-oxypyridine-N-oxy) siliconium chloride in good yield.

Difficulties in the interaction of the free electron pair in diacetophosphides and diacetamides

1968 ◽  
Vol 17 (2) ◽  
pp. 377-380
Author(s):  
R. G. Kostyanovskii ◽  
V. V. Yakshin ◽  
S. L. Zimont ◽  
I. I. Chervin
Keyword(s):  
Free Electron ◽  
Electron Pair ◽  
Free Electron Pair

scholarly journals catena-Poly[[diaquacadmium(II)]-μ2-3-(4-carboxylatophenyl)propionato]

IUCrData ◽  
2019 ◽  
Vol 4 (7) ◽  
Author(s):  
Frederick C. Ezenyilimba ◽  
Richard J. Staples ◽  
Robert L. LaDuca
Keyword(s):  
Hydrogen Bonding ◽  
Coordination Polymer ◽  
Title Compound ◽  
Bound Water ◽  
Polymer Chains ◽  
Water Molecules ◽  
Bonding Mechanisms ◽  
Oriented Parallel ◽  
Trigonal Prismatic

In the title compound, [Cd(C10H8O4)(H2O)2)] n , the CdII cation is coordinated in a distorted trigonal–prismatic fashion. 3-(4-Carboxyphenyl)propionate (cpp) ligands connect the CdII cations into zigzag [Cd(cpp)(H2O)2)] n coordination polymer chains, which are oriented parallel to [101]. The chains aggregate into supramolecular layers oriented parallel to (10\overline{1}) by means of O—H...O hydrogen bonding between bound water molecules and ligating cpp carboxylate O atoms. The layers stack in an ABAB pattern along [100] via other O—H...O hydrogen-bonding mechanisms also involving the bound water molecules. The crystal studied was an inversion twin.

Eine pentagonal pyramidale Koordination des Bismuts. Kristallstruktur von Methylbismutbis( diethyldithiocarbamat) / A Pentagonal Pyramidal Coordination of Bismut. Crystal Structure of Methylbismuthbis( diethyldithiocarbamate)

1979 ◽  
Vol 34 (7) ◽  
pp. 1037-1039 ◽  
Author(s):  
Christian Burschka ◽  
Markus Wieber
Keyword(s):  
Crystal Structure ◽  
Free Electron ◽  
Title Compound ◽  
Crystalline State ◽  
Electron Pair ◽  
Benzene Solution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Free Electron Pair

Abstract Methylbismuth-bis(diethyldithiocarbamate), X-ray The crystal structure of the title compound, recrystallized from ethanol, was solved by means of X-ray diffraction methods and could be refined to an i?-value of 0.050 with 2126 reflections observed. In contrast to its behaviour in benzene solution, where the compound is monomeric, in the crystalline state dimeric units are formed by intermolecular Bi-S-interactions. The bismuth atoms are coordinated in form of a slightly distorted pentagonal pyramid with the free electron pair presumably directed opposite the apical C-atom.

Sign in / Sign up

Export Citation Format

Share Document