Erdalkaliquadratate, II SrC4O4 · 3H2O Typ I [1] / Alkaline-Earth Squarates, II SrC4O4 · 3H2O Type I [1]

1986 ◽  
Vol 41 (12) ◽  
pp. 1490-1494 ◽  
Author(s):  
Christian Robl ◽  
Armin Weiss
Keyword(s):  
Hydrogen Bonding ◽  
Single Crystal ◽  
Alkaline Earth ◽  
Electron System ◽  
Water Molecules ◽  
Type I ◽  
Bond Lengths ◽  
Oxygen Atoms

Abstract In SrC4O4-3H2O (type I), Sr2+ has CN 8. It is surrounded by 3 water molecules and 5 oxygen atoms of 4 different squarate dianions. The C-O and C-C bond lengths are typical of extensive delocalization of the π-electron system. The connection of Sr2+ and C4O42- leads to infinite layers, obviously interlinked by hydrogen bonding.The oxygens of the squarate behave differently: two are Sr-chelating, but simultaneously bound to two additional Sr2+, one is connected with one Sr2+ only, and the fourth is not bound to any Sr2+. The single crystal character remained in principle unchanged during dehydration to SrC4O4 · 1 H2O and subsequent rehydration to the trihydrate. Grinding of a crystal treated in this way led to a new modification of SrC4O4 ·3 H2O.

Erdalkaliquadratate, I BaC4O4 · 3H2O / Alkaline-earth Squarates, I BaC4O4 · 3H2O

1986 ◽  
Vol 41 (12) ◽  
pp. 1485-1489 ◽  
Author(s):  
Christian Robl ◽  
Armin Weiss
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Silica Gel ◽  
Alkaline Earth ◽  
Three Dimensional ◽  
Water Molecules ◽  
Bond Lengths ◽  
Resonance Stabilization ◽  
Aqueous Silica

Abstract BaC4O4-3H2O was prepared by crystallization in aqueous silica gel. The crystal structure is a complicated three-dimensional framework. Ba2+ has CN 8+1. It is surrounded by 5 water molecules and 4 Osquarate atoms (Ba-O distances from 271.1 to 324.2 pm). The squarate dianion is almost planar and shows C -C and C-O bond lengths indicating the existence of resonance stabilization, although one Osquarate atom is not connected to Ba2+ at all. Short water-Osquarate distances hint to strong hydrogen bonding which obviously plays an important part in this structure.

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.

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.

Transition Metal Squarates, II On the Structure of Cubic (MC4O4·2H2O)3CH3COOH·H2O(M=Zn2+,Ni2+)[1]

1986 ◽  
Vol 41 (11) ◽  
pp. 1329-1332 ◽  
Author(s):  
Armin Weiss ◽  
Eugen Riegler ◽  
Christian Robl
Keyword(s):  
Hydrogen Bonding ◽  
Transition Metal ◽  
Metal Ions ◽  
Water Molecules ◽  
Framework Structure ◽  
Space Group ◽  
3 Dimensional ◽  
Monodentate Ligands ◽  
Oxygen Atoms

Abstract The isotypic compounds (MC4O4·2 H2O)3·CH3COOH·H2O(M=Zn2+,Ni2+) crystallize in the cubic space group Pn3n. The 3-dimensional framework structure contains cavities, which may be filled with CH3COOH · H2O . The metal ions are coordinated almost octahedrally by two water molecules and four oxygen atoms of four C4O42- dianions. Thus the squarate dianions act as fourfold monodentate ligands. Strong hydrogen bonding between H2O and C4O42- has to be assumed.

scholarly journals Crystal Structure and Cyclic Voltammetric Studies on the Metal Complexes of N-(Dimethylcarbamothioyl)-4-fluorobenzamide

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Gun Binzet ◽  
Ersan Turunc ◽  
Ulrich Flörke ◽  
Nevzat Külcü ◽  
Hakan Arslan
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Analysis Data ◽  
Complex Compounds ◽  
Planar Geometry ◽  
Cyclic Voltammetric ◽  
Bond Lengths ◽  
H Nmr ◽  
Cyclic Voltammetric Studies ◽  
Oxygen Atoms

We synthesized N-(dimethylcarbamothioyl)-4-fluorobenzamide compound and its copper(II) and nickel(II) complexes. The structures of compounds have been characterized by elemental analysis and spectral data (IR, 1H NMR). Furthermore, crystal and molecular structure of the synthesized complexes have been identified by using single crystal X-ray diffraction data. In the complexes formation the metal atom was coordinated via two sulfur atoms and two oxygen atoms. The single crystal structure of copper(II) and nickel(II) complex exhibits slightly distorted square planar geometry. The oxygen atoms are in a cis configuration. It appeared that the lengths of the thiocarbonyl and carbonyl bonds are longer than the average for C=S and C=O; meanwhile the C‐N bonds in the complex ring appeared to be shorter than the average for C‐N single bonds. These data show that C-O, C-S, and C-N bond lengths of the complexes suggest considerable electronic delocalization in the chelate ring. All bond lengths and angles obtained as a result of the analyses are found to be within experimental error limits. The obtained crystal analysis data shows that the structure of complex compounds is compatible with similar compounds in literature. Electrochemical behavior of complexes has been investigated by cyclic voltammetry technique in aprotic media. From the cyclic voltammetric investigation, both of the complexes have demonstrated electroactive properties.

scholarly journals Crystal structure ofcis-aquachloridobis(1,10-phenanthroline-κ2N,N′)chromium(III) tetrachloridozincate monohydrate from synchrotron data

2015 ◽  
Vol 71 (3) ◽  
pp. 288-290 ◽  
Author(s):  
Dohyun Moon ◽  
Jong-Ha Choi
Keyword(s):  
Hydrogen Bonding ◽  
Three Dimensional ◽  
Water Molecules ◽  
Coordination Environment ◽  
Bond Lengths ◽  
Hydrogen Bonding Pattern ◽  
Dimensional Network ◽  
Distorted Octahedral ◽  
Cl Atom ◽  
Distorted Octahedral Coordination Environment

The structure of the title compound, [CrCl(C12H8N2)2(H2O)][ZnCl4]·H2O, has been determined from synchrotron data. The CrIIIion is bonded to four N atoms from two 1,10-phenanthroline (phen) ligands, one water molecule and a Cl atom in acisarrangement, displaying an overall distorted octahedral coordination environment. The Cr—N(phen) bond lengths are in the range of 2.0495 (18) to 2.0831 (18) Å, while the Cr—Cl and Cr—(OH2) bond lengths are 2.2734 (7) and 1.9986 (17) Å, respectively. The tetrahedral [ZnCl4]2−anion is slightly distorted owing to its involvement in O—H...Cl hydrogen bonding with coordinating and non-coordinating water molecules. The two types of water molecules also interact through O—H...O hydrogen bonds. The observed hydrogen-bonding pattern leads to the formation of a three-dimensional network structure.

Die Kristallstruktur von Zinkformiat-Dihydrat

1977 ◽  
Vol 145 (5-6) ◽  
Author(s):  
N. Burger ◽  
H. Fuess
Keyword(s):  
Hydrogen Bonding ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Water Molecules ◽  
Monoclinic Space Group ◽  
Space Group ◽  
Three Dimensional Structure ◽  
Oxygen Atoms

AbstractZinc formate cristallizes isomorphous to the formates of Mg, Sr, Cd, Mn and Ni in the monoclinic space groupThe structure has been refined including an isotropic extinction correction toThe octahedra of the two nonequivalent zinc atoms are slightly distorted. Zn(l) in (000) is surrounded by six oxygen atoms of the formate groups [distances Zn(l)–O = 2.071 Å–2.145 Å]; the octahedron of Zn(2) in (½½0) consists of the oxygen atoms of the two formate groups and two water molecules [distances Zn(2)–O = 2.053 Å–2.165 Å].The three-dimensional structure is stabilized by hydrogen bonding between formate groups and water molecules.

scholarly journals Crystal structure ofcatena-poly[[[triaquastrontium]-di-μ2-glycinato] dibromide]

2015 ◽  
Vol 71 (7) ◽  
pp. 875-878 ◽  
Author(s):  
Palanisamy Revathi ◽  
Thangavelu Balakrishnan ◽  
Kandasamy Ramamurthi ◽  
Subbiah Thamotharan
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Alkaline Earth ◽  
Three Dimensional ◽  
Water Molecules ◽  
Intermolecular Hydrogen Bonds ◽  
Rotation Axes ◽  
Hydrogen Bonding Interactions ◽  
Carboxylate Groups ◽  
Glycine Molecule

In the title coordination polymer, {[Sr(C2H5NO2)2(H2O)3]Br2}n, the Sr2+ion and one of the water molecules are located on twofold rotation axes. The alkaline earth ion is nine-coordinated by three water O atoms and six O atoms of the carboxylate groups of four glycine ligands, two in a chelating mode and two in a monodentate mode. The glycine molecule exists in a zwitterionic form and bridges the cations into chains parallel to [001]. The Br−counter-anions are located between the chains. Intermolecular hydrogen bonds are formed between the amino and carboxylate groups of neighbouring glycine ligands, generating a head-to-tail sequence. Adjacent head-to-tail sequences are further interconnected by intermolecular N—H...Br hydrogen-bonding interactions into sheets parallel to (100). O—H...Br and O—H...O hydrogen bonds involving the coordinating water molecules are also present, consolidating the three-dimensional hydrogen-bonding network.

Trends in the frequencies of ν(AsOxHx–1) [x = 2–4] in selected As(V)-containing compounds investigated using quantum chemical calculations

2010 ◽  
Vol 88 (1) ◽  
pp. 65-77 ◽  
Author(s):  
Adrian Adamescu ◽  
Holly Gray ◽  
Katherine M.E. Stewart ◽  
I. P. Hamilton ◽  
Hind A. Al-Abadleh
Keyword(s):  
Force Constant ◽  
Density Functional ◽  
Resonance Effect ◽  
Water Molecules ◽  
Functional Theory ◽  
Bond Lengths ◽  
Gas Phase Molecules ◽  
Semi Empirical ◽  
X Ray Absorption ◽  
Oxygen Atoms

The application of computational chemistry to studies in geochemistry is increasingly becoming invaluable in explaining experimentally observed trends for surface interactions of pollutants with sorbents ubiquitous in the environment. We report computational results on factors that affect the force constant of AsOx bonds in As(V)-containing compounds relevant to geochemical environments. Geometries, atomic charges, and stretching frequencies of –AsOxHx–1 (x = 2– 4) moieties in these molecules were calculated using semi-empirical methods (PM3) and density functional theory (B3LYP) for both isolated (gas phase) molecules and hydrated complexes in which the molecules are surrounded by four water molecules. We found that the number of organic substituents has a relatively smaller effect on the force constant of AsOx bonds than protonation. The increase in resonance effect with deprotonation causes As–O bond lengths to increase, and the decrease in resonance in fully deprotonated species with increasing organic substitution causes As–O bond lengths to decrease. In the absence of the resonance effect in fully protonated species, As–O bond lengths increase with more organic substituents. Also, increasing organic substitution causes the charge on the central arsenic atom to decrease. Charges on oxygen atoms in As–OH bonds are more sensitive to deprotonation than to resonance relative to other oxygen atoms in As–O bonds. As expected, frequencies of ν(AsOx) show an inverse relationship with As–O bond lengths upon deprotonation and organic substitution. Our results have implication for the interpretation of infrared and X-ray absorption spectra of adsorbed As(V)-containing compounds.

Crystal structures of [SbF6]− salts of di- and tetrahydrated Ag +, tetrahydrated Pd2 + and hexahydrated Cd2 + cations

2017 ◽  
Vol 232 (5) ◽  
pp. 339-347 ◽  
Author(s):  
Zoran Mazej ◽  
Evgeny Goreshnik
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Crystal Structures ◽  
Water Molecules ◽  
Bond Lengths ◽  
Square Planar ◽  
Oxygen Atoms

AbstractThe [Ag(H2O)2]SbF6, is triclinic, P1̅ (No. 2), with a=6.6419(3) Å, b=7.6327(3) Å, c=11.1338(3) Å, α=95.492(3)°, β=96.994(3)°, γ=113.535(4)°, V=507.13(4) Å3 at 150 K, and Z=3. There are two crystallographically non-equivalent Ag+ cations. The Ag1 is coordinated by two water molecules with Ag–OH2 distances equal to 2.271(2) Å forming in that way a discrete linear [Ag(H2O)2]+ cation. Additionaly, it forms two short Ag···F contacts (2.630(2) Å), resulting in AgO2F2 plaquette, and four long ones (2×3.001(2) Å and 2×3.095(2) Å) with fluorine atoms located below and above the AgO2F2 plaquette. The H2O molecules bridge Ag2 atoms into {–[Ag(μ-OH2)2]–}n infinite chains, with Ag–O distances of 2.367(2)–2.466(2) Å. The [Pd(H2O)4](SbF6)2·4H2O is monoclinic, P21/a (No.14), with a=8.172(2) Å, b=13.202(3) Å, c=8.188(3) Å, β=115.10(1)o, V=799.9(4) Å3 at 200 K, and Z=2. Its crystal structure can be described as an alternation of layers of [Pd(H2O)4]2+ cations (interconnected by H2O molecules) and [SbF6]− anions. It represents the first example where [Pd(H2O)4]2+ has been structurally determined in the solid state. Four oxygen atoms provided by H2O molecules are in almost ideal square-planar arrangement with Pd–O bond lengths 2×2.004(5) Å and 2×2.022(6) Å. The [Cd(H2O)6](SbF6)2, is orthorhombic, Pnnm (No.58), with a=5.5331(2) Å, b=14.5206(4) Å, c=8.9051(3) Å, V=715.47(4) Å3 at 200 K, and Z=2. It consists of [Cd(H2O)6]2+ cations and [SbF6]− anions.

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